12th class (Fsc) Chemistry unit 3 MCQs
51. Dipole moment of the CO2 molecule is:
a. 106D
b. 120D
c. Zero D
d. 140D
52. Which one out of the following oxides is not formed by carbon?
a. C3O2
b. CO
c. CO2
d. C3O4
53. Which one of the following statement does not agree with structure of CO2 ?
a. Four ion pair of electrons
b. C-O bond length is 115p
c. Carbon has one lone pair of electron
d. Dipole moment zero
54. Which one of the following statement does not explain the structure of CO?
a. It has dipole moment 0.112 D
b. It has triple bond between C and O
c. Carbon has one lone pair while oxygen has two lone pairs
d. It is very slighlty plar between C and O
55. Which mineralof silicon due to its greasy nature used in cosmetics?
a. Analcite
b. Zircon
c. Asbestos
d. Talc
56. The pure clay is called:
a. Kaolin
b. Soapstone
c. Analcite
d. Asbestos
57. Which compund of silicon is used as filler in soap to make it heavy:
a. H2SiO3
b. SiO2
c. Silicons
d. Na2SiO3
58. Silica is reacted with sodium carbonate. what a the gas liberated:
a. O2
b. CO
c. O3
d. CO2
59. Which of the following oxide is acidic as well as solid at room temperature:
a. CO2
b. SiO2
c. SnO2
d. pbO2
60. Sodium silicates dissolves in water, The resulting solution is:
a. Amphoteric
b. Acidic
c. Neutral
d. Basic
61. SiO2 is used as:
a. Good conductor
b. Non-conductor
c. Excellent conductor
d. Semi conductor
62. Silicons are used:
a. As lubricants
b. As water repellent
c. In hydraulic systems
d. All of these
63. Red lead is:
a. pbO2
b. RbO
c. pbCrO4
d. pb3O4
64. Which is not used as a pigment in paints:
a. PbO2
b. PbCrO4
c. pb3O4
d. White lead
65. Lead pencil contains:
a. Lead
b. Graphite
c. Lead sulphite
d. Charcoal
66. The color of lead sun oxide is:
a. Black
b. Yellow
c. Red
d. Blue
67. The color of massicot is:
a. Red
b. Blue
c. Black
d. Yellow
68. The color of litharge is:
a. Reddish yellow
b. Reddish brown
c. Brownish red
d. Yellowish green
69. On boiling litharge with water and olive oil along with glycerine a sticky mass is formed called:
a. Lead palmate
b. Leave valerate
c. Lead oleate
d. Lead fumerate
70. What is formula of sandhur?
a. Pb3O4
b. PbO2
c. Pb2O
d. PbO
71. White lead darkness when exposed to air due to presence of?
a. H2Se
b. H2S
c. CO2
d. H2O
72. Pb3O4 is used as:
a. Blue pigment
b. White pigment
c. Silver pigment
d. Red pigment
73. Which metal is used in the thermit process because of its activity:
a. Aluminium
b. Iron
c. Zinc
d. Copper
74. Aluminium oxide is:
a. Amphoteric oxide
b. Acidic oxide
c. Basic oxide
d. None of these
75. Chemical composition of colemaniteis:
a. Na2B4O7 .4H2O
b. Ca2B6 O11 .5H2O
c. CaNaB5 O9 .8H2O
d. CaB4O7 .4H2O