Metals and Their Compound Metals and Their Compound Metals and Their Compound

Metals and Their CompoundMetals and Their CompoundMetals and Their CompoundMetals and Their CompoundMetals and Their CompoundMetals and Their Compound

Metals and Their Compound

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Q.1. Why is it necessary to classify elements periodically?

(a) Elements

(b) Compounds

(d) Elements or Compounds

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2. Consider the following statements:

Metal and non-metal oxides are of different types.
Metal oxides are basic but non-metal oxides are acidic.

Which of the above statement(s) is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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3. Which one of the following is not correct?

(a) Among all the known elements, the majority are metals.

(b) The total number of non-metals is only 22.

(d) None of these.

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Q.4. In the outermost shell of a metal atom, usually how many electrons are present?

(a) Only 1

(b) 1 or 2

(d) 4

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Q.5. Consider the statements:

Metals are electropositive.
Metals can lose their valence electrons to form cations.
Which statement(s) is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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Q.6. Metals can be beaten into thin sheets with hammers. What is this property of metals called?

(a) Ductility (तन्यता)

(b) Malleability (आघातवर्धनीयता)

(d) Diffusion (विसरण)

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Q.7. Which of the following pairs of metals are the most malleable?

(a) Gold and Lead

(b) Silver and Copper

(d) Gold and Silver

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Q.8. Which one of the following statements is correct?

(a) Metals are malleable and non-metals are ductile.

(b) Metals are malleable but lack ductility.

(d) All metals are not equally ductile and malleable.

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Q.9. Which of the following metals has the lowest melting point?

(a) Silver

(b) Sodium

(d) Gallium

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Q.10. Which of the following pairs of metals are found in liquid state at room temperature?

(a) Zinc and Iron

(b) Gallium and Cesium

(d) Copper and Silver

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Q.11. Which of the following statements is NOT correct?

(a) Metals are good conductors of heat and electricity.

(b) The melting and boiling points of metals are higher compared to non-metals.

(d) Graphite conducts electricity but it is not a metal.

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Q.12. Which of the following metals can be cut with a knife?

(a) Sodium

(b) Potassium

(d) Both a and b

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Q.13. Which of the following metals has the lowest density?

(a) Potassium

(b) Magnesium

(d) Gold

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Q.14. Which of the following is an amphoteric oxide?

(a) Al₂O₃

(b) ZnO

(d) All of these

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Q.15. Consider the statements:

Oxides of metals are acidic.
Some oxides of metals are both acidic and basic (amphoteric).

Which statement(s) is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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Q.16. Which of the following shows the correct order of reactivity of metals towards oxygen?

(a) Na > Mg > Zn > Cu

(b) Mg > Na > Zn > Cu

(d) Na > Cu > Zn > Mg

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Q.17. Sodium and Potassium are kept under kerosene or in a vacuum. Why?

(a) These metals remain solid in kerosene or vacuum.

(b) If exposed to air, they catch fire.

(d) These metals have very low density.

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.18. Which metal is used in the construction of hot water tanks?

(a) Copper (तांबा)

(b) Iron (लोहा)

(d) All of these

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Q.19. With which of the following acids does a metal not liberate hydrogen gas?

(a) HCl

(b) H₂SO₄

(d) All of these

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20. Consider the statements:

All ores are minerals.
All minerals are not ores.
Which statement(s) is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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Q.21. What is the unwanted substance found in ores obtained from the Earth’s crust called?

(a) Gangue (गैंग)

(b) Flux (गालक)

(d) Impurity (अशुद्धि)

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22. Smelting and roasting are processes by which:

(a) Impurities (gangue) in the ore are removed

(b) Metal is converted into its oxide

(d) Metal is converted into its ore

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Q.23. Under which conditions is a mineral called an ore?

(a) Extraction of metal from the mineral is cost-effective

(b) Metal can be extracted easily

(d) All of these

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Q.24. The elements that lose electrons to form cations are called:

(a) Metals (धातु)

(b) Non-metals (अधातु)

(d) All of these

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Q.25. Which of the following metals is classified as a strategic metal?

(a) Titanium (Ti)

(b) Chromium (Cr)

(d) All of these

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Q.26. Which of the following metals does not have the property of ductility?

(a) Gold (सोना)

(b) Silver (चांदी)

(d) Copper (तांबा)

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Q.27. Which of the following metals will displace H₂ from dilute acids?

(a) Magnesium (Mg)

(b) Silver (Ag)

(d) All of these

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Q.28. Which of the following statements regarding chemical properties of metals is NOT correct?

(a) Metals have a tendency to lose electrons.

(b) Metals have low ionization energy.

(d) Metal oxides are usually basic or amphoteric.

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Q.29. Consider the statements:

Au, Ag, Pt, and Cu are found in nature in their free state because they are less reactive.
K, Na, Ca, Mg are highly reactive, hence they cannot be found in free state.
Moderately reactive metals like Al, Zn, Fe, Pb are mainly found in the Earth’s crust as oxides, sulfides, or carbonates.

Which statement(s) is/are correct?

(a) Only 1

(b) 1 and 2

(d) 1, 2 and 3

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Q.30. What is the substance mixed with ore to remove impurities (gangue) called?

(a) Gangue (गैंग)

(b) Flux (फ्लक्स)

(d) Metallurgy (धात्विकी)

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Q.31. Which method is generally used for the enrichment of oxide ores?

(a) Hydraulic washing (द्रवचालित धुलाई)

(b) Froth flotation (फेन प्लवन विधि)

(d) Chemical separation (रासायनिक पृथक्करण)

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Q.32. The Bayer process is used for the concentration of which ore?

(a) Hematite (हेमाटाइट)

(b) Chromite (क्रोमाइट)

(d) Bauxite (बॉक्साइट)

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Q.33. The process of strongly heating a sulfide ore in presence of sufficient air to convert the metal into its oxide is called:

(a) Smelting (निस्तापन)

(b) Roasting (भर्जन या जारण)

(d) None of these

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Q.34. The process of heating a metal oxide with coke to convert it into metal is called:

(a) Smelting (निस्तापन)

(b) Roasting (भर्जन या जारण)

(d) None of these

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Q.35. Consider the statements:

Smelting is used to convert carbonate and hydrated oxide ores into pure oxides.
Roasting is used to convert sulfide ores into pure oxides.

Which statement(s) is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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36. Silver and gold are extracted by which method?

(a) Leaching (निक्षालन)

(b) Magnetic separation (चुंबकीय सांद्रण विधि)

(d) Hydraulic washing (द्रवचालित धुलाई)

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37. Semiconductors like Germanium (Ge), Silicon (Si), Boron (B), Iridium (Ir) are refined by which method?

(a) Cupellation (क्यूपेलीकरण)

(b) Zone refining (प्रक्षेत्र शोधन)

(d) Vapour phase method (वाष्पन अवस्था विधि)

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Q.38. Leaching is used for which process in ores?

(a) Oxidation (ऑक्सीकरण)

(b) Concentration (सांद्रण)

(d) Roasting or calcination (जारण या भर्जन)

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Q.39. Which metal is obtained by treating its ore with a dilute solution of sodium cyanide?

(a) Copper (Cu)

(b) Zinc (Zn)

(d) Platinum (Pt)

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41. On which of the following metals does air have no effect?

(a) Gold (सोना)

(b) Sodium (सोडियम)

(d) Copper (तांबा)

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40. Which of the following metals cannot be obtained by reduction with carbon?

(a) Zinc (Zn)

(b) Mercury (Hg)

(d) Lead (Pb)

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42. Metals above hydrogen in the reactivity series:

(a) React with acids to give hydrogen ions

(b) React with acids to liberate hydrogen gas

(d) None of these

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43. Food containers are coated with tin, not zinc, because:

(a) Zinc is more expensive than tin

(b) Zinc has a higher melting point than tin

(d) Zinc is less reactive than tin

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44. The ore whose particles are heavier than the impurities present in it is concentrated by which method?

(a) Froth flotation (फेन प्लवन)

(b) Gravity separation (गुरुत्व पृथक्करण)

(d) Magnetic separation (चुंबकीय पृथक्करण)

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45. Which of the following metals can react with dilute nitric acid to liberate hydrogen gas?

(a) Iron (Fe)

(b) Sodium (Na)

(d) Gold (Au)

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46. Which of the following shows the correct order of reactivity of metals?

(a) Mg > Na > Zn > Cu > Fe

(b) Zn > Mg > Na > Cu > Fe

(d) Na > Zn > Mg > Fe > Cu

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47. Which of the following metals forms amphoteric oxide?

(a) Copper (कॉपर)

(b) Iron (आयरन)

(d) Lead (लेड)

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48. Which of the following metals does not react with cold or hot water?

(a) Magnesium (Mg)

(b) Potassium (K)

(d) Iron (Fe)

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49. Ores in which the ore and impurities (gangue) have different chemical properties are concentrated by which method?

(a) Hand picking (हाथ से चुनकर)

(b) Froth flotation (फेन प्लवन विधि)

(d) Leaching (निक्षालन विधि)

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50. Which of the following statements about roasting (भर्जन/जारण) is NOT correct?

(a) It converts sulfides into oxides

(b) It removes volatile impurities

(d) It converts the ore into powder

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51. In which group and period of the periodic table is sodium (Na) located?

(a) Group 1, Period 1

(b) Group 1, Period 2

(d) Group 1, Period 3

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52. Which alkali metals are found in abundance on the Earth's surface?

(a) Na and K (सोडियम और पोटेशियम)

(b) Na and Li (सोडियम और लिथियम)

(d) Na and Cs (सोडियम और सीजियम)

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53. Which alkali metal is the only one that combines with nitrogen to form a nitride?

(a) Sodium (सोडियम)

(b) Potassium (पोटैशियम)

(d) Cesium (सीजियम)

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54. In Down's process:

(a) Sodium is obtained by electrolysis of sodium chloride

(b) Calcium is obtained by electrolysis of calcium chloride

(d) All of these

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55. Why is calcium chloride mixed with sodium chloride before electrolysis?

(a) To activate sodium chloride (सोडियम क्लोराइड को क्रियाशील करने हेतु)

(b) To obtain sodium from sodium chloride (सोडियम क्लोराइड से सोडियम प्राप्त करने हेतु)

(d) To decrease the melting point of sodium chloride (सोडियम क्लोराइड का द्रवणांक घटाने हेतु)

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Q.56. Consider the following statements:

Aqueous solution of sodium chloride is not used to obtain sodium metal.
Sodium metal is mainly obtained by electrolysis of molten sodium chloride.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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57. The chemical formula of common salt is:

(a) NaCl

(b) NaOH

(d) Na₂CO₃·10H₂O

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58. When common salt (NaCl) is obtained from seawater, which impurity is usually present?

(a) MgCl₂

(b) MgSO₄

(d) All of these (इनमें से सभी)

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59. When common salt is left exposed to air, it becomes damp. The reason is:

(a) CaCl₂

(b) MgCl₂

(d) CaSO₄

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60. What is added to common salt to make it iodized?

(a) KIO₃ (Potassium iodate)

(b) KI (Potassium iodide)

(d) Both a and b (a तथा b दोनों)

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61. Which sodium compound is mixed with ice to prepare a freezing mixture?

(a) NaOH (Sodium hydroxide)

(b) Na₂CO₃ (Sodium carbonate)

(d) NaHCO₃ (Sodium bicarbonate)

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62. Which important compounds are prepared commercially by the Castner-Kellner method?

(a) NaOH (Sodium hydroxide)

(b) KOH (Potassium hydroxide)

(d) NaHCO₃ (Sodium bicarbonate / Baking soda)

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63. Which important sodium compounds are prepared by the Ammonia-soda (Solvay) process?

(a) NaHCO₃ (Sodium bicarbonate)

(b) Na₂CO₃ (Sodium carbonate)

(d) NaOH (Sodium hydroxide)

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65. What is the chemical formula of sodium thiosulfate?

(a) Na₂S₂O₃

(b) Na₂BO₃

(d) Na₂SO₃

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66. In which form is sodium bicarbonate used?

(a) As baking soda (बेकिंग सोडा के रूप में)

(b) As an antacid (ऐंटासीड के रूप में)

(d) All of these (इनमें से सभी)

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67. In kitchens, which is commonly used to make tender dishes or to cook food quickly?

(a) Sodium chloride (NaCl)

(b) Caustic soda (NaOH)

(d) Sodium bicarbonate (NaHCO₃)

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69. Which is used to make bread or cake soft and spongy?

(a) Sodium chloride (NaCl)

(b) Caustic soda (NaOH)

(d) Sodium carbonate (Na₂CO₃)

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70. How much sodium is present in a healthy human body?

(a) 5 g

(b) 0.06 g

(d) 170 g

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71. When pieces of sodium are placed in water:

(a) Floats (तैरता है)

(b) Sinks (डूब जाता है)

(d) None of these (इनमें से कोई नहीं)f

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73. In photography, the chemical commonly used as “hypo” is:

(a) Sodium thiosulfate (Na₂S₂O₃)

(b) Borax salt (Na₂B₄O₇)

(d) Glauber’s salt (Na₂SO₄·10H₂O)

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74. Municipalities commonly use yellow lamps to illuminate streets. Which element is used in these yellow lamps?

(a) Magnesium (मैग्नीशियम)

(b) Neon (नियॉन)

(d) Nitrogen (नाइट्रोजन)

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75. In photography, sodium thiosulfate (hypo) is useful in which way?

(a) It removes unexposed silver bromide (यह अनअपघटित सिल्वर ब्रोमाइड को दूर कर देता है)

(b) To blacken the image (चित्र को काला करने में)

(d) To make the image stain-free (चित्र को धब्बा रहित बनाने में)

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76. What is the chemical name of Chile saltpeter?

(a) Potassium nitrate (KNO₃)

(b) Sodium nitrate (NaNO₃)

(d) Magnesium nitrate (Mg(NO₃)₂)

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77. Which compound is used to purify air in submarines, ships, and hospitals?

(a) Sodium chloride (NaCl)

(b) Sodium bicarbonate (NaHCO₃)

(d) Sodium peroxide (Na₂O₂)

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78. When sodium bicarbonate is heated, which gas is released that makes bread and cake soft and spongy?

(a) CO₂ (Carbon dioxide)

(b) CO (Carbon monoxide)

(d) SO₂ (Sulfur dioxide)

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79. Eno’s salt, which helps reduce stomach acidity, is a mixture of:

(a) Sodium bicarbonate and tartaric acid

(b) Sodium bicarbonate and citric acid

(d) Sodium carbonate and citric acid

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80. What is the chemical formula of Soda Ash?

(a) Na₂CO₃·10H₂O

(b) Na₂CO₃

(d) Na₂SO₄

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81. Which of the following is NOT an ore of magnesium?

(a) Cryolite (क्रायोलाइट)

(b) Carnallite (कार्नेलाइट)

(d) Magnesite (मैग्नेसाइट)

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82. Magnesium is mainly extracted from which ore?

(a) Epsom salt (MgSO₄·7H₂O)

(b) Carnallite (KMgCl₃·6H₂O)

(d) Dolomite (CaMg(CO₃)₂)

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83. Which compound of magnesium is used for making the lining of furnaces?

(a) Magnesium carbonate (MgCO₃)

(b) Magnesium sulfate (MgSO₄)

(d) Magnesium oxide (MgO)

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84. Which of the following metals burns in nitrogen to form a nitride?

(a) Sodium (Na)

(b) Calcium (Ca)

(d) Gold (Au)

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85. Which metal is used for making flash-light ribbons?

(a) Sodium (Na)

(b) Calcium (Ca)

(d) Platinum (Pt)

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86. Which of the following is used to reduce stomach acidity or as an antacid?

(a) Milk of magnesia (Mg(OH)₂ suspension)

(b) Magnesium alba (MgCO₃·Mg(OH)₂·xH₂O)

(d) All of the above

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87. Consider the following statements:

Magnesium oxide is called Milk of Magnesia.
Magnesium hydroxide is called Magnesia.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

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88. Epsom salt chemical formula is—

(a) MgSO₄·7H₂O

(b) FeSO₄·7H₂O

(d) CuSO₄·5H₂O

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89. The organic compound chlorophyll, which gives green color to plants, contains which metal?

(a) Sodium

(b) Magnesium

(d) Silver

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90. The main metallic component present in Sorel cement is —

(a) Potassium

(b) Lithium

(d) Magnesium

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91. Which is the most abundant metal available in the Earth’s crust?

(a) Sodium

(b) Iron

(d) Calcium

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92. In 1827, aluminium metal was first extracted from which substance, though it was very expensive?

(a) Bauxite

(b) Aluminium chloride

(d) Fluorspar

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93. After iron, which metal is most widely used?

(a) Aluminium

(b) Magnesium

(d) Platinum

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94. Who discovered the cheap method of aluminium extraction, due to which the price of aluminium dropped by about 90%?

(a) Hall

(b) Héroult

(d) Both (a) and (b)

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95. Which of the following is an ore of aluminium?

(a) Bauxite

(b) Corundum

(d) All of these

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96. What is the primary ore of aluminium from which aluminium is extracted?

(a) Bauxite

(b) Corundum

(d) All of these

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97. The impurities (gangue) present in bauxite are removed by which method?

(a) Froth flotation

(b) Magnetic separation

(d) Gravity separation

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98. What is the main gangue found along with bauxite ore?

(a) Silica (SiO₂)

(b) Iron oxide

(d) a and b both

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99. What is the chemical name of bauxite?

(a) Aluminium chloride

(b) Alumina

(d) Aluminium sulfate

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100. Aluminium metal is extracted from bauxite by which method?

(a) Electrolytic decomposition

(b) Fractional distillation

(d) Sublimation

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101. Aluminium metal is extracted by the electrolysis of alumina (Al₂O₃), but what difficulty arises in its extraction?

(a) The melting point of pure alumina is very high, i.e., 2348 K

(b) Molten Al₂O₃ is a poor conductor of electricity

(d) All of these

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102. Why is cryolite (Na₃AlF₆) added in the electrolysis of alumina?

(a) To increase electrical conductivity

(b) To lower the melting point of alumina

(d) To reduce the anode effect

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103. Why are cryolite (Na₃AlF₆) and a little fluorspar (CaF₂) mixed in the electrolysis of alumina?

(a) To increase electrical conductivity

(b) To lower the melting point of alumina

(d) Neither (a) nor (b)

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104. When alumina is electrolyzed, pure aluminium is obtained at:

(a) Cathode

(b) Anode

(d) Equally at cathode and anode

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105. Which method is used to remove impurities from bauxite ore?

(a) Hall’s dry process

(b) Bayer’s wet process

(d) All of these

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106. Which of the following is an ore of aluminium?

(a) Turquoise

(b) Mica (Abarkh)

(d) All of these

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107. Although aluminium is more abundant in the Earth's crust than iron, why is aluminium more expensive?

(a) Aluminium is in higher demand than iron

(b) Aluminium is light while iron is heavy

(d) Metallic extraction methods of aluminium are more expensive than those of iron

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108. Which of the following statements about aluminium is NOT correct?

(a) Aluminium hydroxide is amphoteric

(b) Aluminium occurs in a free state in nature

(d) Hot concentrated sulphuric acid reacts with aluminium

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109. Which metal and its alloys are used for making airplanes and rockets?

(a) Magnesium

(b) Iron

(d) Platinum

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110. Which method is used to remove impurities from aluminium obtained by the electrolysis of alumina?

(a) Hoops method

(b) Hall’s method

(d) Serpek method

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111. Which compound is used to make fire-resistant and water-repellent fabrics?

(a) Sodium sulfate

(b) Magnesium sulfate

(d) Aluminium sulfate

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112. What is the chemical formula of common alum (Potash Alum)?

(a) K₂SO₄·Al₂(SO₄)₃·24H₂O

(b) K₂SO₄·Al₂(SO₄)₃·21H₂O

(d) K₂SO₄·Fe₂(SO₄)₃·24H₂O

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113. Ruby (माणिक्य) और Sapphire (नीलम) are oxides of which element?

(a) Copper

(b) Gold

(d) Iron

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114. Which aluminium salt is commonly used to stop bleeding (as a styptic)?

(a) Aluminium chloride

(b) Aluminium nitrate

(d) Potash alum

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115. How does Potash Alum stop bleeding?

(a) Absorption

(b) Coagulation

(d) Diffusion

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116. Which aluminium salt is used for purifying dirty water?

(a) Potash alum

(b) Aluminium nitrate

(d) Aluminium chloride

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117. Which of the following is an alkali soil metal?

(a) Sodium

(b) Lithium (Li)

Above all

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118. Lime stone, marble, chalk, etc. are chemically what?

(a) Calcium oxide

(b) Calcium dioxide

(d) Gypsum

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119. What is the chemical name of Quick-lime and Slaked-lime?

(a) Calcium oxide (b) Calcium hydroxide

(d) Gypsum

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120. Consider the following statements:

Calcium oxide is called quick lime.
Calcium hydroxide is called slaked lime.

Which of the above statements is/are correct?

(a) केवल 1

(b) केवल 2

(d) न तो 1 न ही 2

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121. When limestone (CaCO₃) is heated, it produces:

(a) CaO

(b) Ca(OH)₂

(d) CaCO₃

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122. Which compound is used for whitewashing houses?

(b) Ca(OH)₂

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123. Limestone is:

(a) CaO

(b) Ca(OH)₂

(d) None of these

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124. What is the chemical formula of Plaster of Paris?

(a) CaSO₄·½ H₂O

(b) (CaSO₄)₂·H₂O

(d) a and b

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125. Consider the following statements:

If gypsum is heated above 393 K, it becomes completely anhydrous, forming calcium sulfate.
If gypsum is carefully heated up to 393 K, Plaster of Paris is formed.

Which statement(s) is/are correct?

(a) Only 1

(b) Only 2

(d) neither 1 and 2

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126. In surgery, which is used in the form of casts to set and join broken bones?

(a) Gypsum

(b) Plaster of Paris

(d) Calcium oxide

124 / 360

127. Which calcium compound is widely used for making statues?

(a) कैल्शियम कार्बोनेट

(b) कैल्शियम आक्साइड

(d) प्लास्टर ऑफ पैरिस

125 / 360

Which of the following statements about Plaster of Paris (POP) is NOT correct?

(a) Its chemical name is Calcium sulfate hemihydrate.

(b) Plaster of Paris has a special property of setting with water.

(d) None of these

126 / 360

129. When an aqueous solution of sodium carbonate is added to an aqueous solution of calcium chloride or calcium nitrate, a white precipitate is obtained. What is it?

(a) CaO

(b) Ca(OH)2

(d) CaC2

127 / 360

130.How much calcium is present in the body of an average human?

(a) 25 g

(b) 1200 g

(d) 170 g

128 / 360

131. Approximately 99% of the total calcium present in the body is found in –

(a) Bones and teeth

(b) Blood plasma

(d) Hormones

129 / 360

132.Which of the following is not correct?

(a) The reaction between calcium oxide and water is exothermic.

(b) Calcium oxide is an amphoteric oxide.

(d) Calcium oxide reacts with ammonium chloride to produce ammonia gas.

130 / 360

133. What is the main ore of calcium from which calcium metal is extracted?

(a) Calcium chloride

(b) Calcium carbonate

(d) Phosphate

131 / 360

134.Hydrolith and Nitrolith are compounds of which metal?

(a) Hydrogen

(b) Nitrogen

(d) Aluminium

132 / 360

135.What is the chemical formula of dolomite?

(a) Na₃AlF₆

(b) CaCO₃·MgCO₃

(d) KCl·MgCl₃·6H₂O

133 / 360

136 What is calcium phosphate used for?

(a) In the preparation of acetylene gas

(b) In the toothpaste industry

(d) As a desiccant

134 / 360

137.Which of the following statements about calcium oxide (CaO) is not correct?

(a) Heating limestone in a kiln at 1273 K gives calcium oxide or lime.

(b) The process of converting limestone to lime (CaO) is called calcining.

(d) The melting point of calcium oxide is extremely low, about 373 K.

135 / 360

138.On a commercial scale, bleaching powder is prepared by—

(a) Reaction of chlorine gas with lime

(b) Reaction of chlorine gas with slaked lime

(d) Mixing calcium oxide with water

136 / 360

139.By Hoesen-Klever or Böhme plant, which important substance is prepared?

(a) Bleaching powder

(b) Cement

(d) Soap

137 / 360

140.Consider the following statements about bleaching powder:

Bleaching powder is a yellowish-white powder that has the smell of chlorine gas.
Chemically, bleaching powder is calcium oxychloride.
When bleaching powder is left open in air, it slowly releases chlorine gas.

(a) 1 और 2

(b) केवल 2

(d) 1, 2 और 3

138 / 360

141.When bleaching powder is left exposed to air, it loses its effectiveness because –

(a) It reacts with oxygen and gets oxidized.

b) It reacts with carbon dioxide and releases chlorine gas.

(d) None of these

139 / 360

142.Bleaching powder is used for –

(a) To bleach cotton and jute in textile industries

(b) As a reagent in chemical industries

(d) All of these

140 / 360

145.Which of the following is called lime chloride?

(a) Bleaching powder

(b) Calcium oxide

(d) Gypsum

141 / 360

145.Which statement about bleaching powder is false?

(a) It is highly soluble in water

(b) It is an oxidizing agent

(d) It liberates chlorine gas with a dilute acid

142 / 360

146.In the extraction of calcium metal, calcium fluoride is added to calcium chloride because –

(a) It acts as an oxidizing agent

(b) It acts as a reducing agent

(d) It makes calcium chloride electrolyzable

143 / 360

147.Asbestos is made of –

(a) Calcium and magnesium

(b) Copper, zinc, and manganese

(d) Calcium and zinc

144 / 360

148.Which of the following statements about iron (Fe) is not correct?

(a) Among metals used, iron is the most widely used.

(b) Iron is the second most abundant metal in the earth's crust.

(d) In the earth’s crust, iron is found as sulfide, oxide, and carbonate ores.

145 / 360

149.Which is the most important iron ore from which iron is extracted?

(a) Hematite

(b) Magnetite

(d) Iron pyrite

146 / 360

150.From which of the following minerals is iron not extracted?(FeS₂)

(a) Hematite

(b) Magnetite

(d) Iron pyrites(FeS₂)

147 / 360

151.Which is the main gangue mixed in the iron ore hematite?

(a) Silica

(b) Calcium carbonate

(d) None of these

148 / 360

152.Hematite is chemically-

(a) Fe₃O₄

(b) Fe₂O₃

(d) FeCO₃

149 / 360

153.From hematite ore, the gangue is removed by which method?

(a) Hydraulic washing

(b) Winnowing (Fan method)

(d) Precipitation

150 / 360

154.Regarding the blast furnace used in iron extraction, which one is not correct?

(a) Iron is obtained as a result of the reduction, not oxidation, of hematite in the blast furnace.

(b) The outer walls of a blast furnace are made of steel sheets and the inner walls of fire bricks.

(d) During extraction, the lower part of the furnace is hottest, and the upper part is coolest.

151 / 360

156.Before putting into the blast furnace, hematite ore is mixed with coke and limestone. What is this mixture called?

(a) Batch

(b) Charge

(d) Precipitate

152 / 360

157.Which flux is used to remove gangue from hematite ore?

(a) CaO

(b) Ca(OH)₂

(d) CaOCl₂

153 / 360

158.Consider the following statements:

In the blast furnace used for iron extraction, the lower part contains the reducing agent carbon monoxide.
The uppermost part of the blast furnace contains the reducing agent carbon.

Which of the statements is/are correct?

(a) केवल 1

(b) केवल 2

(d) न तो 1 न ही 2

154 / 360

159.The iron obtained from a blast furnace is—

(a) Pig iron

(b) Wrought iron

(d) None of these

155 / 360

160.Which of the following is not true?

(a) The iron obtained from the lower part of a blast furnace is called pig iron.

(b) Pig iron is very hard and brittle due to the presence of carbon.

(d) Pig iron contains 0.25 to 1.5% carbon.

156 / 360

161. By which method is wrought iron obtained from pig iron?

(a) Puddling process

(b) Bessemer process

(d) Cementation process

157 / 360

162. What is the percentage of carbon in wrought iron?

(a) 2–5%

(b) 0.25–1.5%

(d) None of these

158 / 360

163. In obtaining iron from hematite, in what form is limestone used?

(a) Flux

(b) Metallizer

(d) Oxidizing agent

159 / 360

165. Consider the following statements:

In white cast iron, most of the carbon is present in a combined form.
In grey cast iron, most of the carbon is distributed in the form of fine graphite flakes throughout the mass.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

160 / 360

164. In a blast furnace, by which substance is iron oxide reduced?

(a) Limestone

(b) Silica

(d) Carbon monoxide

161 / 360

166. Which of the following is Green Vitriol?

(a) FeSO₄·2H₂O

(b) CuSO₄·5H₂O

(d) FeSO₄·(NH₄)₂SO₄·6H₂O

162 / 360

167. Which of the following is called Fool’s Gold?

(a) Iron sulfide

(b) Ferric chloride

(d) Pyrolusite

163 / 360

168. Which compound of iron is used to stop bleeding from a cut?

(a) Ferrous sulfate (FeSO₄)

(b) Ferric chloride (FeCl₃)

(d) Ferrous dioxide (Fe₂O₃)

164 / 360

169. What is the chemical formula of Mohr’s Salt?

(a) K₂SO₄·Al₂(SO₄)₃·24H₂O

(b) FeSO₄·(NH₄)₂SO₄·6H₂O

(d) Na₂B₄O₇·10H₂O

165 / 360

171. Pyrolusite is the ore of which metal?

(a) Iron

(b) Manganese

(d) Silver

166 / 360

170. Excess of which metal in the body causes the disease called Siderosis?

(a) Iron

(b) Copper

(d) Sodium

167 / 360

172. The deep purple compound used as an antiseptic and disinfectant is:

(a) Potassium nitrate

(b) Sodium thiosulfate

(d) कैल्शियम फॉस्फेट

168 / 360

173. Which compound is known as “Red Medicine”?

(a) Calcium phosphate

(b) Potassium permanganate

(d) Green vitriol

169 / 360

174. Which of the following is NOT correct about copper?

(a) Copper is found in nature in both free and combined states

(b) Copper was the first metal used by primitive humans

(d) Copper is yellow in color like gold

170 / 360

176. Which of the following is a copper sulfide ore?

(a) Malachite

(b) Azurite

(d) Copper pyrites

171 / 360

175. Which two metals are NOT silver-colored?

(a) Sodium and Gold

(b) Copper and Gold

(d) Nickel and Zinc

172 / 360

177. In the extraction of copper from non-sulfide ores, which is used as a reducing agent?

(a) Carbon

(b) Carbon monoxide

(d) Chromium

173 / 360

178. Extraction of copper from sulfide ores, i.e., copper pyrites, is difficult. Why?

(a) In this ore, iron sulfide is present as the main impurity.

(b) Copper has a greater tendency to combine with sulfur than with oxygen.

(d) All of the above

174 / 360

179. Consider the following statements:

A mixture of Cu₂S and FeS is called Copper Matte.
Copper Matte contains about 70% copper.
Copper from Copper Matte is obtained by the Bessemerization process.

Which of the above statements is/are correct?

(a) Only 1

(b) 1 and 2

(d) 1 and 3

175 / 360

180. From very low-grade ores containing extremely small amounts of copper, which method is used for extraction?

(a) Using green wood sticks

(b) Electrolytic decomposition

(d) All of these

176 / 360

181. Copper metal is used in:

(a) Making electrical appliances

(b) Coin and utensil manufacture

(d) All of these

177 / 360

182. Consider the following statements:

Copper does not react with dilute HCl and dilute H₂SO₄.
Copper reacts with concentrated HCl and concentrated H₂SO₄.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

178 / 360

183. When anhydrous copper sulfate is added to water, the color of the water becomes:

(a) Blue

(b) Green

(d) Yellow

179 / 360

184. Which of the following copper compounds is used as a disinfectant?

(a) Cuprous oxide (Cu₂O)

(b) Cupric oxide (CuO)

(d) All of these

180 / 360

185. Which compound is known as Blue Vitriol or Blue Stone?

(a) Copper sulfate

(b) Zinc sulfate

(d) Ferric sulfate

181 / 360

186. Which disease occurs when the copper content in the human body increases?

(a) Siderosis

(b) Wilson’s disease

(d) Beri-beri

182 / 360

187. Which chemical is used to destroy algae in water tanks?

(a) Nitric acid

(b) Zinc sulfate

(d) Magnesium sulfate

183 / 360

188. Which element is the enemy of copper?

(a) Carbon

(b) Sulfur

(d) Hydrogen

184 / 360

189. The chemical formula of “Tritiya” is:

(a) CuS

(b) Cu(OH)₂

(d) CuSO₄·5H₂O

185 / 360

190. Which metal is used for making calorimeters and lightning conductors?

(a) Iron

(b) Copper

(d) Steel

186 / 360

191. Which of the following is NOT an ore of zinc?

(a) Calamine

(b) Willemite

(d) Tenorite

187 / 360

192. From which two major ores is zinc extracted?

(a) Zinc blend and Calamine

(b) Zinc blend and Zincite

(d) Calamine and Zinc spinel

188 / 360

193. What is the approximate zinc content in snake venom 🐍 ?

(a) 0.1–1%

(b) 0.5–2%

(d) 1–10%

189 / 360

194. The phosphorus used in making ointments, creams, etc., is chemically:

(a) Zinc sulfate

(b) Zinc oxide

(d) Zinc phosphide

190 / 360

196. To protect wooden objects from insects, which compound is applied on them?

(a) Zinc chloride

(b) Zinc oxide

(d) Zinc sulfide

191 / 360

197. Which of the following compounds exhibits phosphorescence?

(a) Zinc sulfate

(b) Zinc oxide

(d) Zinc chloride

192 / 360

198. The chemical formula of White Vitriol is:

(a) CuSO₄·5H₂O

(b) ZnSO₄·7H₂O

(d) MgSO₄·7H₂O

193 / 360

199. What is the mixture of zinc sulfide (ZnS) and barium sulfate (BaSO₄) called?

(a) White vitriol

(b) Phosphor wool

(d) Lithopone

194 / 360

200. Which of the following is used as a rodenticide (rat poison)?

(a) Zinc carbonate

(b) Zinc chloride

(d) Zinc sulfide

195 / 360

201. The substance used in dyeing as a mordant is:

(a) Aluminium sulfate

(b) Calcium hydroxide

(d) Zinc phosphate

196 / 360

202. The metal that reacts with hot sodium hydroxide solution to produce hydrogen gas is:

(a) Zn

(b) Ag

(d) Fe

197 / 360

203. Which of the following is an ore of silver?

(a) Silver glance

(b) Horn silver

(d) All of these

198 / 360

204. Silver and gold are extracted by:

(a) Leaching process

(b) Hydraulic washing method

(d) Froth flotation method

199 / 360

205. In the leaching process for extracting silver and gold, which of the following is used?

(a) KCN

(b) NaCN

(d) FeCl₂

200 / 360

206. Calaverite and Sylvanite are ores of which metal?

(a) Silver

(b) Gold

(d) All of these

201 / 360

208. Which metal is called “White Gold” and “Adam’s Catalyst”?

(a) Silver

(b) Copper

(d) Platinum

202 / 360

209. The cyanide process is used for extracting which metal?

(a) Silver

(b) Gold

(d) Copper

203 / 360

210. Silver is mainly extracted from which ore?

(a) Argentite

(b) Native silver

(d) Cerargyrite

204 / 360

212. Silver nitrate is usually stored in colored bottles. Why?

(a) It gets oxidized in air

(b) It evaporates in white bottles

(d) It decomposes in sunlight

205 / 360

211. Which compound is used to mark a voter’s finger during voting?

(a) Silver chloride

(b) Silver bromide

(d) Silver nitrate

206 / 360

213. Which of the following compounds decomposes in sunlight?

(a) AgCl

(b) AgBr

(d) None of these

207 / 360

214. It is advised not to eat eggs with a silver spoon. Why?

(a) Silver reacts with sulfur in the egg and gets destroyed

(b) Silver saturates the unsaturated fats in the egg

(d) Silver makes the egg white toxic

208 / 360

215. Which of the following metals is found in the free (native) state?

(a) Gold

(b) Silver

(d) All of these

209 / 360

216. Which metal is called the “King of Metals”?

(a) Gold

(b) Silver

(d) Iron

210 / 360

217. Consider the following statements:

Gold and silver are found in nature in the free (native) state.
Gold and silver are not found in combined (ore) form in nature.

Which of the statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

211 / 360

218. Which compound is used in making anti-venom syringes?

Calcium gluconate

Auric chloride

Calcium gluconate

212 / 360

219. Which of the following statements is NOT correct?

(a) Gold and platinum do not react with acids.

(b) Gold and platinum dissolve in aqua regia.

(d) The reason gold and platinum dissolve in aqua regia is nascent chlorine.

213 / 360

220. Which of the following metals is obtained by reacting its ore with an aqueous solution of sodium cyanide?

(a) Cu

(b) Zn

(d) Ag

214 / 360

221. 100% pure gold is:

(a) 18 carat

(b) 20 carat

(d) 0.22 carat

215 / 360

222. What is added to gold to make it harder?

(a) Copper

(b) Silver

(d) Both A and B

216 / 360

223. Hallmark signs are applied on which products?

(a) Petroleum products

(b) Gold ornaments

(d) Liquid food products

217 / 360

224. What is the percentage of pure gold in 18-carat gold alloy?

(a) 50%

(b) 75%

(d) 25%

218 / 360

225. Which of the following metals has the highest density?

(a) Gold

(b) Silver

(d) Zinc

219 / 360

226. Gold and silver are used in making jewelry due to which property?

(a) Gold and silver are rare metals

(b) Gold and silver are highly malleable and ductile

(d) Gold and silver are the only metals that are yellow and white in color

220 / 360

227. Which of the following metals remains in liquid state at ordinary temperature?

(a) Cesium

(b) Gallium

(d) Bromine

221 / 360

228. Mercury is extracted from which ore?

(a) Galena

(b) Cinnabar

(d) Sylvanite

222 / 360

229. Which of the following metals is neither malleable nor ductile?

(a) Mercury

(b) Iron

(d) Gold

223 / 360

230. Which of the following statements is NOT correct?

(a) Mercury is also known as quicksilver

(b) Mercury, when vigorously shaken with fat or sugar, turns into a brown powder

(d) Mercury does not dissolve in aqua regia

224 / 360

233. Which metal is commonly used in thermometers and barometers?

(a) Barium

(b) Mercury

(d) Silver

225 / 360

234. Mercury is commonly used in thermometers because of which property?

(a) High density

(b) Low viscosity

(d) High thermal conductivity

226 / 360

235. Which gas is filled in a normal tubular light (fluorescent tube)?

(a) Argon with sodium vapor

(b) Neon with sodium vapor

(d) Neon with mercury vapor

227 / 360

236. Which chemical, used in medicines as “Makar Dhwaj,” has the following chemical formula?

(a) HgCl₂

(b) HgS

(d) HgSO₄

228 / 360

238. Mercury combines with other metals to form a metallic solution, which is called:

(a) Quick silver

(b) Amalgam

(d) Corrosive sublimate

229 / 360

237. Chemically, what is Sindoor?

(a) Potassium nitrate

(b) Calcium carbonate

(d) Mercuric sulfide

230 / 360

240. Mercury is stored in a container made of which metal?

(a) Silver

(b) Lead

(d) Platinum

231 / 360

239. Which of the following metal combinations is an amalgam?

(a) Zinc - Copper

(b) Copper - Tin

(d) Mercury - Iron

232 / 360

241. Which of the following mercury compounds is used as a disinfectant?

(a) HgCl₂

(b) Hg₂Cl₂

(d) HgS

233 / 360

242. Which is the most stable element?

(a) Iron

(b) Lead

(d) Silver

234 / 360

243. Which of the following is a non-metal that conducts heat and electricity?

(a) Copper

(b) Graphite

(d) Tungsten

235 / 360

244. Lead is extracted from which ore?

(a) Galena

(b) Cinnabar

(d) Turquoise

236 / 360

245. Lithiarge has which nature?

(a) Acidic

(b) Basic

(d) All of these

237 / 360

246. Which lead compound is used in the manufacture of storage batteries?

(a) Lead oxide

(b) Lead dioxide

(d) Lead acetate

238 / 360

247. Which of the following compounds is called “Sugar of Lead” or “Inorganic Sugar”?

(a) Lead oxide

(b) Lead dioxide

(d) Lead acetate

239 / 360

248. Which of the following metals is used for writing on paper?

(a) Lead

(b) Iron

(d) Mercury

240 / 360

249. Lead pipes are not used for drinking water because:

(a) They dissolve in aerated water to produce toxic lead hydroxide.

(b) They dissolve in aerated water to produce toxic lead oxide.

(d) None of these.

241 / 360

250. Which metal is used in storage (rechargeable) batteries?

(a) Copper

(b) Lead

(d) Zinc

242 / 360

251. What is the chemical name of Galena?

(a) Lead sulfate

(b) Lead oxide

(d) Calcium sulfate

243 / 360

252. In vehicles, which metal pollutes the air due to the burning of petrol?

(a) Mercury

(b) Cadmium

(d) Carbon dioxide

244 / 360

253. Which of the following is a radioactive metal?

(a) Thorium

(b) Uranium

(d) All of these

245 / 360

254. Which radioactive element is abundantly found in the monazite sand along the Kerala coast in India?

(a) Thorium

(b) Uranium

(d) Radium

246 / 360

255. Which of the following is called a “Hope Metal”?

(a) Thorium

(b) Uranium

(d) Radium

247 / 360

257. Which of the following isotopes of uranium does NOT exhibit radioactivity?

(a) U-234

(b) U-235

(d) None of these

248 / 360

258. Which isotope of uranium is used as fuel in nuclear reactors?

(a) U-234

(b) U-235

(d) All of these

249 / 360

259. Consider the following statements:

Natural uranium contains 0.7% of U-235.
Enriched uranium contains 2–3% of U-235.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

250 / 360

260. The substance called “Yellowcake” that is smuggled across borders is:

(a) Heroin

(b) Colloidal gold

(d) Uranium oxide

251 / 360

261. On 6 August 1945, the “Little Boy” atomic bomb dropped on Hiroshima (Japan) by the USA used which element?

(a) Plutonium

(b) Uranium

(d) Sodium

252 / 360

262. On 9 August 1945, the “Fat Man” atomic bomb dropped on Nagasaki (Japan) by the USA used which element?

(a) Plutonium

(b) Uranium

(d) Sodium

253 / 360

263. Which element acts as fuel in a nuclear reactor?

(a) Uranium

(b) Thorium

(d) All of these

254 / 360

264. Which element was first artificially produced?

(a) Neptunium

(b) Plutonium

(d) Technetium

255 / 360

265. Who discovered the new element Plutonium (atomic number 94)?

(a) Marie Curie

(b) Glenn Seaborg

(d) Ernest O. Lawrence

256 / 360

266. Which of the following is the heaviest metal?

(a) Copper

(b) Uranium

(d) Silver

257 / 360

268. What is the chemical symbol of Tungsten?

(a) W

(b) As

(d) Tm

258 / 360

269. Which of the following metals cannot be easily cut with a knife?

(a) Sodium

(b) Aluminium

(d) Potassium

259 / 360

270. Which element is used as a timekeeper in atomic clocks?

(a) Potassium

(b) Cesium

(d) Magnesium

260 / 360

271. During fireworks, the green color is seen due to the chloride salt of which element?

(a) Barium

(b) Sodium

(d) Strontium

261 / 360

272. In fireworks, the bright red color is due to the chloride salt of which element?

(a) Sodium

(b) Barium

(d) Strontium

262 / 360

273. Among the following metal combinations, which contains the lightest and the heaviest metal?

(a) Lithium & Mercury

(b) Lithium & Osmium

(d) Aluminium & Mercury

263 / 360

274. Which element is used in making rechargeable batteries for mobile phones and laptops?

(a) Beryllium

(b) Sodium

(d) Magnesium

264 / 360

275. Which element is used in the manufacture of transistors, solar panels, and microprocessors?

(a) Silicon

(b) Titanium

(d) Zinc

265 / 360

276. Which of the following metals is as strong as steel but weighs only half as much?

(a) Titanium

(b) Silicon

(d) Arsenic

266 / 360

277. Who discovered the radioactive elements Radium and Polonium?

(a) Benjamin Franklin

(b) Madam Curie

(d) Irène Joliot-Curie

267 / 360

278. Which of the following elements is used in the manufacture of fertilizers?

(a) Fluorine

(b) Lead

(d) Aluminium

268 / 360

279. Which chemical substance is coated on audio and video tapes?

(a) Iron oxide

(b) Sodium dioxide

(d) Calcium oxide

269 / 360

280. What is the percentage of lead in a lead pencil?

(a) 0%

(b) 100%

(d) 65%

270 / 360

281. Which of the following elements exhibits unique magnetic properties at room temperature?

(a) Copper

(b) Aluminium

(d) Ruthenium

271 / 360

282. The filament of an electric bulb is made of:

(a) Tungsten

(b) Nichrome

(d) Aluminium

272 / 360

283. Which of the following substances is very hard and highly tensile?

(a) Carborundum

(b) Tungsten

(d) Nichrome

273 / 360

284. Consider the following statements:

“Degana” in Rajasthan is famous for uranium production.
“Jadugoda” in Jharkhand is famous for tungsten production.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

274 / 360

285. Identify the metal which is chemically inert in nature.

(a) Chromium

(b) Gold

(d) Cobalt

275 / 360

286. Which of the following is in liquid form at room temperature?

(a) Lithium

(b) Sodium

(d) Cesium

276 / 360

287. Who discovered Potassium?

(a) Humphry Davy

(b) Alan Turing

(d) Tim Berners-Lee

277 / 360

288. Which of the following is not a component of chlorophyll?

(a) Hydrogen

(b) Magnesium

(d) Calcium

278 / 360

289. The most chemically inert metal pollutant from automobile exhaust is:

(a) Lead

(b) Copper

(d) Mercury

279 / 360

290. Which of the following compounds is commonly used in mouthwashes and toothpastes?

(a) Suhaga (Mercury(II) sulfide)

(b) Shora (Sodium bicarbonate)

(d) Sodium chloride (NaCl)

280 / 360

291. Which of the following metals is used for making electric wires?

(a) Silver

(b) Copper

(d) Lead

281 / 360

292. Which of the following compounds is known as “Red Liquor”?

(a) Lead acetate

(b) Minium manganate

(d) Nitrolim

282 / 360

293. The Ellingham Diagram is used to determine:

(a) The amount of metal present in an ore

(b) The metal used in extraction

(d) The reactivity series of metals

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294. In the aluminothermic process, aluminum acts as:

(a) Oxidizing agent

(b) Reducing agent

(d) Catalyst

284 / 360

295. Which substance is used for drying gases?

(a) Calcium carbonate

(b) Sodium carbonate

(d) Calcium oxide

285 / 360

296. Which alkali metal has the lowest melting point?

(a) Potassium (K)

(b) Sodium (Na)

(d) Rubidium (Rb)

286 / 360

297. K₂CO₃ (Potassium carbonate) is not prepared by the Solvay process because:

(a) KHCO₃ is unstable

(b) KHCO₃ is soluble in water

(d) All of these

287 / 360

298. Which of the following metals is used in fireworks to produce bright white light?

(a) Sodium

(b) Magnesium

(d) Silver

288 / 360

299. Which of the following statements is correct?

(a) Potassium is kept immersed in kerosene.

(b) Sodium is found in free state.

(d) Silver reacts with hot water.

289 / 360

300. KMnO₄ (Potassium permanganate) is used in which of the following forms?

(a) Pesticide

(b) Fertilizer

(d) Antiseptic

290 / 360

301. Regarding corrosion, which of the following is NOT correct?

(a) The chemical effect on the surface of metals by moisture, air, or chemicals is called corrosion.

(b) Oxygen, carbon dioxide, water vapor, sulfur dioxide, and hydrogen sulfide in air are responsible for corrosion.

(d) Corrosion is limited only to iron; other metals do not corrode.

291 / 360

302. Consider the following statements:

Corrosion causes deterioration of metals.
Sometimes corrosion can also be beneficial for metals.

Which of the above statements is/are correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

292 / 360

303. When a piece of iron is exposed to moist air for a few days, a brown layer forms on its surface. What is it called?

(a) Rust

(b) Tarnish

(d) Turquoise

293 / 360

304. For the rusting of iron, the presence of which is essential?

(a) Oxygen

(b) Water vapor (moisture)

(d) None of these

294 / 360

305. Consider the following statements:

Both oxygen and moisture are essential for the rusting of iron.
The hydrated form of iron(III) oxide is called rust.
The amount of water in iron oxide keeps varying, so rust is represented as Fe₂O₃·xH₂O.

Which of the above statements is/are correct?

(a) Only 1

(b) 1 and 3

(d) 1, 2, and 3

295 / 360

306. When copper is exposed to moist air for a long time, a green layer forms on its surface. What is it called?

(a) Turquoise

(b) Patina

(d) Tarnish

296 / 360

307. The green layer formed on the surface of copper when exposed to moist air is chemically:

(a) CuCO₃

(b) Cu(OH)₂

(d) CuSO₄

297 / 360

308. Rust formed on iron is chemically:

(a) Ferric oxide (Fe₂O₃)

(b) Ferric hydroxide (Fe(OH)₃)

(d) None of these

298 / 360

309. The green layer (patina) on copper can be removed with the help of:

(a) Common salt

(b) Lemon

(d) Baking soda

299 / 360

310. When a silver item is exposed to air for a long time, its surface becomes black. The reason is:

(a) Presence of SO₂ in air

(b) Presence of H₂S in air

(d) None of these

300 / 360

311. The black layer formed on silver when it corrodes is called:

(a) Tarnish

(b) Rust

(d) Turquoise

301 / 360

312. When silver items are exposed to air for a long time, their surface becomes tarnished due to:

(a) Formation of Ag₂S

(b) Formation of AgOH

(d) Formation of AgCl

302 / 360

313. Which of the following is NOT correct?

(a) When aluminum is exposed to air, a layer of Al₂O₃ forms, which prevents further corrosion.

(b) The patina on copper prevents further corrosion.

(d) Rust formed on iron is flaky and sticks to iron, preventing further corrosion of the metal.

303 / 360

314. Due to rusting, the weight of iron:

(a) Increases

(b) Decreases

(d) None of these

304 / 360

315. On which of the following metals does the oxide layer act as a protective layer?

(a) Iron

(b) Aluminum

(d) Copper

305 / 360

316. Coating the surface of a metal with tin, nickel, chromium, copper, etc., to prevent its corrosion is called:

(a) Galvanisation

(b) Chrome plating

(d) None of these

306 / 360

317. Coating iron with zinc to prevent corrosion is called:

(a) Galvanisation

(b) Chrome plating

(d) All of these

307 / 360

318. Coating aluminum with an oxide layer to prevent corrosion is called:

(a) Galvanisation

(b) Chrome plating

(d) None of these

308 / 360

319. By which of the following methods can corrosion of metals be prevented?

(a) Coating the metal surface with a thin layer of grease or varnish

(b) Painting the metal surface with acid-resistant paints

(d) All of these

309 / 360

321. Paint applied on the surface of iron prevents rusting because it:

(a) Reacts chemically with iron

(b) Prevents carbon dioxide from coming in contact with iron

(d) Prevents oxygen and moisture from coming in contact with iron

310 / 360

322. The pure form of iron is called:

(a) Pig iron

(b) Wrought iron

(d) Cast iron

311 / 360

323. Galvanising iron prevents its corrosion because:

(a) Zinc is more reactive than iron, so the effect of air acts on zinc and not on iron

(b) The melting point of iron increases

(d) None of these

312 / 360

324. Which of the following minerals does not contain oxygen?

(a) Bauxite

(b) Hematite

(d) Cryolite

313 / 360

325. Which of the following statements is NOT correct?

(a) Pure iron is not useful.

(b) Adding other substances to any metal changes its properties.

(d) While making alloys, only metals can be mixed; non-metals cannot be added.

314 / 360

326. A homogeneous mixture of two or more metals, or a metal and a non-metal, is called:

(a) Alloy

(b) Compound metal

(d) Suspension

315 / 360

327. Consider the following statements:

If an alloy contains mercury, it is called an amalgam.
The electrical conductivity of an alloy is less than that of pure metals or constituent metals.
Sometimes the melting point of an alloy is lower than that of its constituent metals.

Which of the above statements are correct?

(a) 1 and 2

(b) Only 3

(d) Only 2

316 / 360

328. Which of the following statements is correct?

(a) Pure gold is 24 carat, very soft, and cannot be used directly for jewelry.

(b) To make gold harder, it is alloyed with silver or copper.

(d) All of these

317 / 360

329. The malleability and ductility of an alloy, compared to its constituent metals, are:

(a) More

(b) Less

(d) None of these

318 / 360

330. The melting point and electrical conductivity of an alloy, compared to its constituent metals, are:

(a) Less

(b) More

(d) None of these

319 / 360

331. Consider the following statements:

Converting metals into alloys increases their strength and quality.
Alloys are corrosion-resistant.

Which of the above statements is correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

320 / 360

332. Which of the following is not an alloy?

(a) Steel

(b) Brass

(d) Zinc

321 / 360

333. Steel is mainly an alloy of:

(a) Iron and Carbon

(b) Iron and Aluminium

(d) Iron and Tungsten

322 / 360

334. Consider the following statements:

The carbon content in steel lies between wrought iron and pig iron.
The carbon percentage in steel is 0.10–1.5%.

Which of the above statements is correct?

(a) Only 1

(b) Only 2

(d) Neither 1 nor 2

323 / 360

335. Steel is produced by:

(a) Bessemer process

(b) Haber process

(d) Contact process

324 / 360

336. Consider the following statements:

Pig iron is converted to steel by the cementation process.
Steel is made from wrought iron by the Bessemer process.
Nowadays, high-quality steel is mostly produced from wrought iron using the Linz-Donawitz process.

Which of the above statements is correct?

(a) Only 1

(b) Only 2

(d) 1, 2 and 3

325 / 360

337. Which of the following is the most modern method of producing steel from iron?

(a) Siemens-Martin process

(b) Linz-Donawitz (LD) process

(d) Both a and b

326 / 360

338. Which of the following statements is correct?

(a) The carbon content in steel varies from 0.1 to 1.5%

(b) Mild steel contains 0.1–0.4% carbon

(d) All of these

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339. Hard steel is heated to 1123 K and then plunged into cold water to make it even harder. What is this process called?

(a) Quenching

(b) Tempering

(d) None of these

328 / 360

340. If quenched steel is heated and then cooled slowly, it becomes more ductile and less brittle. What is this process called?

(a) Quenching

(b) Tempering

(d) None of these

329 / 360

341. Heating steel to a red-hot temperature and then cooling it slowly to make it soft is called:

(a) Quenching

(b) Tempering

(d) None of these

330 / 360

342. Which of the following steels is extremely hard and strong?

(a) Manganese steel

(b) Chromium steel

(d) Silica steel

331 / 360

343. Helmets and rock crushing machinery are made from which type of steel?

(a) Manganese steel

(b) Cobalt steel

(d) Stainless steel

332 / 360

344. What is the percentage of manganese in manganese steel?

(a) 7–20%

(b) 15–20%

(d) 15%

333 / 360

345. Which steel is used in transformers and electromagnets?

(a) Cobalt steel

(b) Silicon steel

(d) Stainless steel

334 / 360

346. Which steel is acid-resistant and is used to make pumps and pipes for transporting acids?

(a) Manganese steel

(b) Cobalt steel

(d) Nickel steel

335 / 360

347. A permanent magnet is made from which material?

(a) Soft iron

(b) Steel

(d) Cobalt

336 / 360

348. Permanent magnets are made from which type of steel?

(a) Cobalt steel

(b) Manganese steel

(d) Stainless steel

337 / 360

349. To make stainless steel, which important metal is added with iron?

(a) Aluminum

(b) Chromium

(d) Carbon

338 / 360

350. Which important metals are used to make stainless steel?

(a) Chromium & Nickel

(b) Tungsten & Vanadium

(d) Nickel & Cobalt

339 / 360

351. Parts of airplanes, motor cars, and bicycles are made from which steel?

(a) Manganese steel

(b) Chromium & Nickel steel

(d) Silica steel

340 / 360

352. What is added to steel to increase its hardness?

(a) Carbon

(b) Manganese

(d) Chromium

341 / 360

353. Which steel is used to make high-speed machines and drilling tools?

(a) Cobalt steel

(b) Silicon steel

(d) Stainless steel

342 / 360

354. Consider the following statements:

If steel contains 46% nickel, it is used to make scientific instruments and equipment.
If steel contains 36% nickel, it is used to make lamp bulbs and radio valves.

Which of the above statements is correct?

Both 1 and 2

343 / 360

355. Which alloy is used for making weighing scales, light equipment, and similar items?

(a) Magnesium

(b) Lumin

(d) Brass

344 / 360

356. Which is a very strong and highly corrosion-resistant alloy “Bronze”?

(a) Copper & Zinc

(b) Copper & Tin

(d) Aluminum & Copper

345 / 360

357. The alloy ‘Brass’ used for making utensils, screws, nuts, and bolts is –

(a) Copper & Zinc

(b) Copper & Tin

(d) Copper & Silver

346 / 360

358. Which elements are included in stainless steel?

(a) Iron & Carbon

(b) Iron, Nickel & Chromium

(d) Iron, Copper & Carbon

347 / 360

359. Which alloy is used for making heating elements in electrical appliances?

(a) German Silver

(b) Solder

(d) Nichrome

348 / 360

360. “German Silver” used in making utensils is an alloy of:

(a) Copper, Silver, and Nickel

(b) Copper, Zinc, and Aluminium

(d) Copper, Nickel, and Aluminium

349 / 360

361. Rolled Gold is an alloy of:

(a) Copper and Silver

(b) Copper and Gold

(d) Copper and Aluminium

350 / 360

362. Which element is not present in German Silver?

(a) Silver

(b) Nickel

(d) Copper

351 / 360

363. Which of the following is not a proper alloy?

(a) Brass – Copper and Zinc

(b) Stainless Steel – Iron and Chromium

(d) Rose Gold – Gold and Copper

352 / 360

364. Which of the following is not a proper alloy?

(a) Brass – Copper and Zinc

(b) Bronze – Copper and Tin

(d) Magnalium – Aluminum and Manganese

353 / 360

365. Gun metal is an alloy of –

(a) Copper, Tin, and Ferrous

(b) Copper, Ferrous, and Zinc

(d) Copper and Zinc

354 / 360

368. An alloy containing 90% Copper and 10% Tin is –

(a) Brass

(b) German Silver

(d) Bronze

355 / 360

366. Manganin, used in making electrical instruments, is an alloy of –

(a) Copper, Aluminium, and Tin

(b) Copper, Zinc, and Nickel

(d) Copper, Tin, and Phosphorus

356 / 360

369. By which of the following processes does a metal become stronger?

(a) Electroplating

(b) Refining

(d) Annealing

357 / 360

370. Which of the following statements is correct?

(a) Iron rusts when it comes in contact with dry oxygen gas.

(b) Iron rusts in airless water.

(d) None of these.

358 / 360

371. The solder used in electronics, pipeline metal sheets, and electric wire welding is an alloy of –

(a) Lead and Mercury

(b) Lead and Tin

(d) Tin and Zinc

359 / 360

372. In the alloy Duralumin (used in pressure cookers and aircraft structures), along with aluminium and copper, which other metals are present in small amounts?

(a) Magnesium

(b) Manganese

(d) Neither A nor B

360 / 360

373. Consider the following statements –