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Q51. Cryolite is added in the electrolysis of alumina because
- Ato increase electrical conductivity
- BTo reduce the carbon content of alumina
- CTo reduce the anode effect
- DTo separate impurities from alumina
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Answer: B) To reduce the carbon content of alumina
Q52. Which of the following salts is found in the highest quantity in human bones?
- Amagnesium chloride
- Bcalcium carbonate
- Ccalcium phosphate
- Dsodium chloride
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Answer: C) calcium phosphate
Q53. Calcium fluoride is added to calcium chloride in the extraction of calcium metal because
- Ait lowers the melting point
- Bit acts as a desiccant
- CIt acts as an oxidizer
- DMakes calcium chloride an electrolyte.
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Answer: A) it lowers the melting point
Q54. The chemical formula of Plaster of Paris is
- ACaSO⁴ 5H²O
- B2CaSO⁴ H²O
- C(CaSO⁴)² 2H ²O
- DCaSO⁴MgO
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Answer: B) 2CaSO⁴ H²O
Q55. Which one of the following is the chemical formula of gypsum, a constituent of cement?
- ACa²SiO⁴
- BCaSO⁴ 2H ²O
- CCaO
- DCaSO⁴ 3H ²O
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Answer: B) CaSO⁴ 2H ²O
Q56. 'Chalk' and 'marble' are different forms of which of the following?
- ACalcium Hydrogen Carbonate
- Bcalcium carbonate
- CCalcium Acetate
- Dsodium carbonate
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Answer: B) calcium carbonate
Q57. Which of the following is the primary constituent of 'pearl'?
- Acalcium sulfate
- Bcalcium carbonate
- Cpotassium sulphate
- Dcalcium peroxide
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Answer: B) calcium carbonate
Q58. The chemical formula of quick lime is
- ACaO
- BCa(OH)²
- CCaCO³
- DCaCl²
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Answer: A) CaO
Q59. Which of the following is 'marble'?
- ACaCO³
- BCaSO⁴
- CMgCO³
- DCaHCO³
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Answer: A) CaCO³
Q60. Bleaching powder is
- ACaOCI
- BCaOCl²
- CCaOCl³
- DCaOC⁴
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Answer: B) CaOCl²
Q61. Dolomite is the ore of which of the following metals?
- Astrontium
- Bpotassium
- Caluminum
- DCalcium
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Answer: D) Calcium
Q62. What is the chemical name of quicklime?
- Acalcium chloride
- Bcalcium oxide
- Ccalcium hydroxide
- Dcalcium carbonate
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Answer: B) calcium oxide
Q63. The reaction of quicklime (CaO) with water to form slaked lime (Ca(OH)²) is an example of what?
- Adisplacement reaction
- Bendothermic reaction
- Cdecomposition reaction
- Dexothermic reaction
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Answer: D) exothermic reaction
Q64. What is used as bandages in surgery?
- Acalcium sulphate
- Bcalcium chloride
- Caluminum sulfate
- Dcalcium phosphate
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Answer: A) calcium sulphate
Q65. The chemical name of plaster of Paris is
- Acalcium chloride
- BCalcium Nitrate
- CCalcium Sulfate Hydrate
- Dnone of these
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Answer: C) Calcium Sulfate Hydrate
Q66. Plaster of Paris is made of
- Amarble
- Bcement
- CGypsum
- Dlimestone
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Answer: C) Gypsum
Q67. The chemical name of bleaching powder is
- Acalcium oxychloride
- Bsodium bicarbonate
- Ccalcium hydroxide
- Dcalcium carbonate
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Answer: A) calcium oxychloride
Q68. The popular name of calcium sulphate used by doctors, painters, craftsmen etc. is
- Alime of soda
- Bpotassium permanganate
- CGypsum
- Dplaster of Paris
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Answer: D) plaster of Paris
Q69. What is asbestos made of?
- Acalcium and magnesium
- Bcopper, zinc and manganese
- CLead and iron
- DCalcium and Zinc
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Answer: A) calcium and magnesium
Q70. Bleaching powder is prepared by passing through which of the following?
- Achlorine from slaked lime
- Boxygen from slaked lime
- CCO² from the touch of extinguished
- Dchlorine from quicklime
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Answer: A) chlorine from slaked lime
Q71. The 'Heinzclever method' is the commercial method of production of?
- Acaustic soda
- Bnitric acid
- CSulphuric end
- Dbleaching powder
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Answer: D) bleaching powder
Q72. Which statement is false for 'bleaching powder'?
- AIt is more soluble in water
- BIt is a light yellow powder
- CIt is an oxidizing agent.
- DIt releases chlorine when reacted with dilute acids.
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Answer: A) It is more soluble in water
Q73. Leaving bleaching powder open for a long time reduces its activity. Why does this happen?
- Areacts with CO² to release CI²
- Breacts with CO² to release O²
- Creacts with CO² to release CH⁴
- Dnone of these
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Answer: A) reacts with CO² to release CI²
Q74. Which of the following statements is correct about bleaching powder and DDT?
- ABoth are inorganic compounds. Both contain chlorine compounds.
- BBoth are organic compounds
- CBoth contain chlorine compounds.
- DBoth contain calcium compounds.
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Answer: C) Both contain chlorine compounds.
Q75. Which of the following is not an ore of iron?
- ACuprite
- BHematite
- CMagnetite
- DSiderite
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Answer: A) Cuprite