12th class (Fsc) Chemistry unit 4 MCQs
101. Which catalyst is used in contact process?
a. SO3
b. Fe2O3
c. Ag2O
d. V2O5
102. Which of the following specie has the maximum number of unpaired electrons?
a. O3
b. O
c. O4
d. O2
103. Phosphrous panatachloride sublimes at about:
a. 100oC
b. 50oC
c. 80oC
d. 70oC
104. Out of all element of group. A the highest ionization energy is possessed by:
a. Sb
b. N
c. Bi
d. P
105. Monovalency of heavier element’s group n A can be explained on the basis of:
a. Their large sizes
b. Low ionization
c. To electro negativity values
d. Inter pair effect
106. The most electronegative element in group VA is:
a. He
b. Sb
c. SO2
d. N
107. The element whose inorganic minerals are not much abundant in earth crust:
a. Na
b. Li
c. O
d. N
108. Laughing gas is chemically:
a. NO2
b. NO
c. N2O4
d. N2O
109. The brown gas formed, when metals reduces HNO3 to:
a. N2O3
b. NO
c. N2O5
d. NO2
110. Nitric acid can be transported in a container made up of:
a. Al
b. Zn
c. Cu
d. None of these
111. Which metal is rendered passive by HSO3 due to formation of a film of metal oxide over the metal:
a. Co
b. Pt
c. Mn
d. Sn
112. The metal which gives NO gas will dil. HNO3:
a. Hg
b. Zn
c. Sn
d. Cu
113. Which halogen reacts spontaneously with Au(s) to produce Au3+ ?
a. l2
b. Br2
c. Cl2
d. F2
114. Nitric acid can be tranported in a container made up of;
a. Cu
b. Al
c. Zn
d. None of these
115. Which of the following gas evolved when cooper reacts with dil. HNO3 ?
a. NO2
b. NO
c. N2O
d. None
116. The metal which gives NO gas with dill.HNO3.
a. Hg
b. Nz
c. Sn
d. Cu
117. Molecular formula of white phosphorus is:
a. P3
b. P4
c. P2
d. P
118. In phosphorous one of the 3p electron can be promoted to a vacant 3d orbitals giving:
a. 4 unpaired electron in the valence shell
b. 2 unpaired electron in the valence shell
c. 5 unpaired electron in the valence shell
d. 3 unpaired electron in the valence shell
119. Which of the following is not property of phosphorus:
a. Rich source of phosphorus is bone ash
b. It means high bearing
c. It does not exist in allotropic forms
d. Does not exist free in nature
120. Sulpher is an essential constituent of;
a. Protein
b. Plant
c. Chlorophyll
d. All of these
121. The most reactive allotropic form of phosphorus is:
a. Black
b. White
c. Red
d.None of these
122. Indicate the hybridization of P in PCl5 :
a. d2Sp3
b. Sp2
c. dsp3
d. dsp2
123. Which one of the following shows phosphorescence?
a. White phosphorous
b. Yellow phosphorous
c. Red phosphorous
d. Black phosphorous
124. Ortho phosphoric acid has melting point:
a. 41oC
b. 49oC
c. 50oC
d. 45oC
125. S,Se,Te an Po are called:
a. Halogens
b. Conjugate
c. Chalcogens
d. Alkali metals
126. Out of all elements og group VIA, highest melting and boiling points is shown by the element:
a. S
b. Te
c. Pb
d. Se
127. Bone as contains:
a. 90 Ca3 (PO4)2
b. 80% P
c. 90% 90
d. 80% Ca3 (PO4)2
128. Atomic number of Te is:
a. 65
b. 52
c. 80
d. 60
129. The highest ionization energy is possessed by:
a. Bismith
b. Nitrogen
c. Antimony
d. Phosphorus
130. Among group V A elements, the most electro negative is:
a. P
b. Sb
c. As
d. N
131. Which of the following contains 48% oxygen:
a. CaCO3
b. SiO2
c. H2O2
d. BaCO3
132. At 18oC the specific gravity of H2SO4 is:
a. 2.101
b. 1.819
c. 1.71
d. 1.834
133. Which of the following statement is incorrect:
a. H2SO4 acts as a strong dehydrating agent
b. H2SO4 acts as a strong oxidizing agent
c. H2SO4 acts as a strong sulphonating agent
d. H2SO4 acts as a strong reducing agent
134. when sugar is treated with con. H2SO4 it become black due to:
a. Hydrolysis
b. Decolourization
c. Hydration
d. Dedhydration
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