12th class (Fsc) Chemistry unit 3 MCQs
76. Which element forms an ion with charge +3:
a. Carbon
b. Beryllium
c. Silicon
d. Aluminium
77. Which electronic configuration corresponds to an element of group-IIIA of the periodic table:
a. 1s2 , 2s2 , 2p6, 3s2 , 3p1
b. 1s2 , 2s2 , 2p6, 3s2 , 3p2
c. 1s2 , 2s2 , 2p6
d. 1s2 , 2s2 , 2p6, 3s2 , 3p3
78. Which element among the following …… belong to group IV A of the periodic table:
a. Lead
b. Barium
c. Oxygen
d. Iodine
79. Boric acid cannot be used:
a. In soda bottles
b. As antiseptic in medicine
c. For enamels and glazes
d. For washing eyes
80. Which of the following element is not present abundantly in earth’s crust?
a. Sodium
b. Silicon
c. Oxygen
d. Aluminium
81. Tincal is a mineral of;
a. Si
b. A1
c. C
d. B
82. The chief ore of aluminium is:
a. AI2O3
b. Na2AIF6
c. AI2O3 .H2O
d. AI2O3 .2H2O
83. Tincal is a mineral of:
a. Si
b. A1
c. C
d. B
84. The cheif ore of aluminum is:
a. Both a and b
b. Na2AIF4
c. None of these
d. AI2O3 .2H2O
85. Which one is the most toxic?
a. CO2
b. Carbon
c. SO2
d. CO
86. Which one of the element gives acidic oxide?
a. Sb
b. N
c. Bi
d. As
87. Which one of the folloing elements forms weakly acidic oxide?
a. Sulphur
b. Aluminum
c. Chlorine
d. Phosphorous
88. Kaolin is a mineral of:
a. Silicon
b. Carbon
c. Aluminum
d. Magnesium
89. Which one of the following elements is trace element:
a. Sulphur
b. Copper
c. Calcium
d. Nitorgen
90. The compound which forms bead in borax bead test is:
a. Metal borate
b. Metal oxide
c. Metal meta borate
d. Metal boride
91. The metal which does not give borax bead test is:
a. Ni
b. Cu
c. Al
d. Cr
92. which is used in the leather industry?
a. Boric oxide
b. Borax
c. Tetra boric acid
d. Boric acid
93. The aqueous solution of borax is:
a. Amphoteric
b. Alkaline
c. Neutral
d. Acidic
94. In borax bead test, when borax is heated with cobalt oxide. its forms bead of:
a. Red color
b. Black color
c. Green color
d. Blue color
95. In borax bead test, color of cupric borates are:
a. Green
b. Red
c. Colorless
d. Blue
96. Asbestos is commonly used in making:
a. Soft board
b. wall board
c. Hard board
d. Black board
97. Which one is more stable?
a. NaH2BO3
b. H2BO2
c. NaBO2
d. Na2B4O7
98. Orthoboric acid when heated to red hot gives:
a. Meta boric acid
b. Boric anhydride
c. Tetra boric acid
d. pyroboric acid
99. A following is used in making fire proof clothes:
a. Kaolin
b. Water glass
c. Asbestos
d. Borax glass
100. Which metal is used in the thermite process because of its activity:
a. Aluminum
b. Iron
c. Zinc
d. Copper
101. Aluminum oxide is:
a. Amphoteric oxide
b. Acidic oxide
c. None of these
d. Basic oxide
102. Which metal is used in the flash light photography because of its activity:
a. Aluminum
b. Iron
c. Zinc
d. Copper
103. Which oxide is amphoteric in nature:
a. MgO
b. AI2O3
c. SO3
d. Cl2O7
104. The element which atoms amphoteric oxide is:
a. Magnesium
b. Beryllium
c. calcium
d. Sodium
105. The bond in SiCI4 is:
a. Covalent
b. Ionic
c. Partly covalent
d. Partly ionic
106. If temperature is dropped from 100 to 0oC the viscostly of petroleum oil may:
a. Increase 100 times
b. Increase 4 times
c. Decrease 100 times
d. Decrease 4 times
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