12th class (Fsc) Chemistry unit 2 MCQs
51. In the Nelson’s cell used for the manufacture of NaOH. the cathode is made of:
a. Mercury
b. Steel tube lined with asbestos
c. Carbon
d. Iron
52. Cement contains gypsum:
a. 0.2%
b. 3%
c. 0.3%
d. 2%
53. When gypsum is heated above 100 oC, it loses.
a. 3/4 water of crystallization
b. 1/4 water of crystallization
c. All of its water of crystallization
d. 1/2 water of crystallization
54. When some water is added to plaster of paris, it becomes hard and expands:
a. 4%
b. 1%
c. 2%
d. 10%
55. Gypsum is a:
a. Natural polymer
b. Synthetic polymer
c. Dead plant men
d. Mineral
56. …… is necessary for development of leaves and tends to accumulate in leave and bark:
a. Gypsum
b. NO
c. Nitrogen
d. Calcium
57. Motar can be used in the palce of:
a. Cement
b. Glass
c. Asbestos
d. NaCL2
58. The process of setting of cement under water is essentially:
a. A reduction proces
b. An oxidation process
c. A hydration process
d. A doable decomposition process
59. Plaster of Paris hardens by:
a. Changing into CaCO3
b. Giving off CO2
c. Giving outer water
d. Utilizing water
60. Gypsum is added to clinker during cement manufacture to:
a. Blind the particles of calcium silicate
b. Decrease the rate of setting of cement
c. Facilities the formation of colloidal gel
d. All of above
61. Gypsum is applied to the soil as a source of:
a. K and P
b. Ca and S
c. Ca and P
d. N and S
62. The commercial name of CaO is:
a. Marble
b. Gypsum
c. Limestone
d. Lime
63. Mortar is prepare fromthe mixture of:
a. MgCl2 and slica
b. Slaked, lime, sand and water
c. Lime, cement, silica
d. None of these
64. Lime is used:
a. As dehydrating agent
b. For refining of metals
c. In paper industry
d. All of these
65. An adequate supply of Ca to the plant is essential for optimum activity of microorganisms that produce:
a. For the supply of available phosphorous in the soil
b. To stimulate development of root hairs
c. For normal leave development
d. All of these
66. Magnesium is an essential constituent of:
a. Carbohydrate
b. Blood
c. Protines
d. Chlorophyll
67. Calcium carbide on hydrogen produced:
a. Ethyne
b. Ethane
c. Methane
d. Ethyne
68. Chemical formula of slaked lime is:
a. Ca(OH)2
b. CaCO3
c. CaSO4
d. Ca(OH)2H2O
69. Sulphur has an influence on chlorophyll development in plant leaves, in the absence of sulphur, colour of chlorophyll chnages:
a. Pale green
b. Yellow
c. Violet
d. Red
70. Which one of the following does not belongs to alkaline-earth metals?
a. Ba
b. Be
c. Rn
d. Ra
71. The oxides of beryllium are:
a. Amphoteric
b. Acidic
c. Mg2+
d. Basic
72. Which ion will have the maximum value of heat of hydration?
a. Ba2+
b. Na+
c. Mg2+
d. Cs2+
73. which of the following is not an alkali metal?
a. Rubidium
b. Francium
c. Radium
d. Caesium
74. Which of the following sulphate is not suitable in water?
a. Zinc sulphate
b. Sodium sulphate
c. Barium sulphate
d. Potassium sulphate
75. The element caesium bears resemblance with:
a. Both of these metals
b. Ca
c. Cr
d. None of these metals