Chemical Bonding and Molecular Structure (Questions 101 – 150)

101. In which of the following molecules are all the bonds not equal?
     1. \( \text{AlF}_3 \)
     2. \( \text{NF}_3 \)
     3. \( \text{ClF}_3 \)
     4. \( \text{BF}_3 \)
102. Which of the following compound is covalent?
     1. \( \text{H}_2 \)
     2. KCl
     3. \( \text{Na}_2\text{S} \)
     4. CaO
103. Which of the following molecular species has unpaired electron (s)?
     1. \( \text{N}_2 \)
     2. \( \text{F}_2 \)
     3. \( \text{O}_2^- \)
     4. \( \text{O}_2^{2-} \)
104. The correct order of bond angles is:
     1. \( \text{PF}_3 < \text{PCl}_3 < \text{PBr}_3 < \text{PI}_3 \)
     2. \( \text{PF}_3 < \text{PBr}_3 < \text{PCl}_3 < \text{PI}_3 \)
     3. \( \text{PI}_3 < \text{PBr}_3 < \text{PCl}_3 < \text{PF}_3 \)
     4. \( \text{PF}_3 > \text{PCl}_3 < \text{PBr}_3 < \text{PI}_3 \)
105. If the bond length and dipole moment of a diatomic molecule are 1.25 Å and 1.0 D respectively, what is the per cent ionic character of the bond?
     1. 10.66
     2. 12.33
     3. 16.66
     4. 19.33
106. The molecule which does not exhibit dipole moment is
     1. \( \text{NH}_3 \)
     2. \( \text{CHCl}_3 \)
     3. \( \text{H}_2\text{O} \)
     4. \( \text{CCl}_4 \)
107. \( \text{N}_2 \) accept electron and convert into \( \text{N}_2^- \), where this electron goes?
     1. Antibonding \( \pi \)-molecular orbital
     2. Bonding \( \pi \)-molecular orbital
     3. \( \sigma \)-bonding molecular orbital
     4. \( \sigma \)-antibonding molecular orbital
108. The correct order of radii is:
     1. \( \text{N} < \text{Be} < \text{B} \)
     2. \( \text{F}^- < \text{O}^{2-} < \text{N}^{3-} \)
     3. \( \text{Na} < \text{Li} < \text{K} \)
     4. \( \text{Fe}^{3+} < \text{Fe}^{2+} < \text{Fe}^{4+} \)
109. The bond order is maximum in:
     1. \( \text{H}_2 \)
     2. \( \text{H}_2^+ \)
     3. \( \text{He}_2 \)
     4. \( \text{He}_2^+ \)
110. Which of the following atoms has minimum covalent radius?
     1. Si
     2. N
     3. C
     4. B
111. The screening effect of \( d \)-electrons is:
     1. Equal to the \( p \)-electrons
     2. Much more than \( p \)-electrons
     3. Same as \( f \)-electrons
     4. Less than \( p \)-electrons
112. Which of the following statement is wrong?
     1. The stability of hydrides increase from \( \text{NH}_3 \) to \( \text{BiH}_3 \) in group 15 of the periodic table.
     2. Nitrogen cannot form \( d\pi – p\pi \) bond.
     3. Single N—N bond is weaker than the single P—P bond.
     4. \( \text{N}_2\text{O}_4 \) has two resonance structure
113. The molecule having permanent dipole moment is:
     1. \( \text{SF}_4 \)
     2. \( \text{XeF}_4 \)
     3. \( \text{SiF}_4 \)
     4. \( \text{BF}_3 \)
114. Unusually high boiling point of water is result of
     1. Intermolecular hydrogen bonding
     2. Intramolecular hydrogen bonding
     3. Both intra and inter molecular hydrogen bonding
     4. High specific heat
115. Which of the following is least ionic?
     1. \( \text{CaF}_2 \)
     2. \( \text{CaBr}_2 \)
     3. \( \text{CaI}_2 \)
     4. \( \text{CaCl}_2 \)
116. What bond order does \( \text{O}_2^{2-} \) have?
     1. 1
     2. 2
     3. 3
     4. 1/3
117. A compound contains X, Y and Z atoms. The oxidation states of X, Y and Z are +2, +2 and -2 respectively. The possible formula of the compound is
     1. \( XYZ_2 \)
     2. \( Y_2(XZ_3)_2 \)
     3. \( X_3(Y_4Z)_2 \)
     4. \( X_3(YZ_4)_3 \)
118. Which one of the following is a non-polar molecule?
     1. \( \text{CCl}_4 \)
     2. \( \text{CHCl}_3 \)
     3. \( \text{CH}_2\text{Cl}_2 \)
     4. \( \text{CH}_3\text{Cl} \)
119. Which one of the following has the regular tetrahedral structure? (Atomic numbers B = 5, S = 16, Ni = 28, Xe = 54)
     1. \( \text{XeF}_4 \)
     2. \( \text{SF}_4 \)
     3. \( \text{BF}_4^- \)
     4. \( [\text{Ni(CN)}_3]^{2-} \)
120. If the dipole moment of toluene and nitro-benzene are 0.43 D and 3.93 D, then what is the expected dipole moment of p-nitro toluene?
     1. 3.50 D
     2. 2.18 D
     3. 4.36 D
     4. 5.30 D
121. Which of the following is most stable?
     1. \( \text{Pb}^{2+} \)
     2. \( \text{Ge}^{2+} \)
     3. \( \text{Si}^{2+} \)
     4. \( \text{Sn}^{2+} \)
122. In which of the following compound \( sp^2 \) hybridisation is absent?
     1. \( \text{CH}_2 = \text{CH} – \text{CH} = \text{CH}_2 \)
     2. \( \text{CH} \equiv \text{C} – \text{CH}_2 – \text{CH}_3 \)
     3. \( \text{CH}_2 – \text{CH} = \text{CH}_2 \)
     4. \( \text{CH}_2 = \text{CH} – \text{CH}_2 – \text{CH}_3 \)
123. Which one of the following pairs of species has the same bond order:
     1. \( \text{NO}^+ \) and \( \text{CN}^+ \)
     2. \( \text{CN}^- \) and \( \text{NO}^+ \)
     3. \( \text{CN}^- \) and \( \text{CN}^+ \)
     4. \( \text{O}_2^- \) and \( \text{CN}^- \)
124. Which of the following characteristics regarding halogens is not correct?
     1. Ionization energy decreases with increase in atomic number.
     2. Electronegativity decreases with increase in atomic number.
     3. Electron affinity decreases with increase in atomic number.
     4. Enthalpy of fusion increases with increase in atomic number.
125. The number of S – S bonds in sulphur trioxide is
     1. Three
     2. Two
     3. One
     4. Zero
126. The low density of ice compared to water is due to
     1. Induced dipole – induced dipole interactions
     2. Dipole – induced dipole interaction
     3. Hydrogen bonding interactions
     4. Dipole –dipole interaction
127. Consider the following molecules or ions
     (i) \( \text{H}_2\text{O} \) (ii) \( \text{NH}_4^+ \) (iii) \( \text{SO}_4^{2-} \)
     (iv) \( \text{ClO}_4^- \) (v) \( \text{NH}_3 \)
     \( sp^3 \) hybridisation is involved in the formation of
     1. (i), (ii) (v) only
     2. (i), (ii) only
     3. (ii) only
     4. (i), (ii), (iii), (iv) and (v)
128. Which of the following compounds has dipole moment approximately equal to that of chlorobenzene?
     1. \( o \)-dichlorobenzene
     2. \( m \)-dichlorobenzene
     3. \( p \)-dichlorobenzene
     4. \( p \)-chloronitrobenzene
129. Which of the following overlaps leads to bonding? (Note: Visual structure diagrams were omitted from the source text)
     1. a
     2. b
     3. c
     4. d
130. Which of the following is correct?
     1. The number of electrons present in the valence shell of S in \( \text{SF}_6 \) is 12.
     2. The rates of ionic reactions are very low.
     3. According to VSEPR theory, \( \text{SnCl}_2 \) is a linear molecule.
     4. The correct order of ability to form ionic compounds among \( \text{Na}^+ \), \( \text{Mg}^{2+} \) and \( \text{Al}^{3+} \) is \( \text{Al}^{3+} > \text{Mg}^{2+} > \text{Na}^+ \).
131. The number of sigma and pi bonds in peroxodisulphuric acid are respectively
     1. 9 and 4
     2. 11 and 4
     3. 4 and 8
     4. 4 and 9
132. Which is not a paramagnetic species?
     1. \( \text{O}_2 \)
     2. \( \text{O}_2^+ \)
     3. \( \text{O}_2^- \)
     4. \( \text{O}_2^{2-} \)
133. In piperidine, N-H, N atom has hybridization: (Note: Visual diagram omitted)
     1. \( sp \)
     2. \( sp^2 \)
     3. \( sp^3 \)
     4. \( dsp^2 \)
134. Electron deficient species are known as:
     1. Lewis acids
     2. Hydrophilic
     3. Nucleophiles
     4. Lewis bases
135. The molecule having three folds of axis of symmetry is:
     1. \( \text{NH}_3 \)
     2. \( \text{PCl}_5 \)
     3. \( \text{SO}_2 \)
     4. \( \text{CO}_2 \)
136. The structure of \( \text{ICl}_2^- \) is:
     1. Trigonal
     2. Octahedral
     3. Square planar
     4. Distorted trigonal bipyramid
137. Among the following the molecule with the highest dipole moment is
     1. \( \text{CH}_3\text{Cl} \)
     2. \( \text{CH}_2\text{Cl}_2 \)
     3. \( \text{CHCl}_3 \)
     4. \( \text{CCl}_4 \)
138. Which of the following isnot isostructural with \( \text{SiCl}_4 \)?
     1. \( \text{PO}_4^{3-} \)
     2. \( \text{NH}_4^+ \)
     3. \( \text{SCl}_4 \)
     4. \( \text{SO}_4^{2-} \)
139. A molecule which cannot exist theoretically is:
     1. \( \text{SF}_4 \)
     2. \( \text{OF}_2 \)
     3. \( \text{OF}_4 \)
     4. \( \text{O}_2\text{F}_2 \)
140. An atom \( X \) has three valence electrons and atom \( Y \) has six valence electrons. The compound formed between them will have the formula
     1. \( X_2Y_6 \)
     2. \( XY_2 \)
     3. \( X_2Y_3 \)
     4. \( X_3Y_2 \)
141. Which one is polar molecule among the following?
     1. \( \text{CH}_4 \)
     2. \( \text{CCl}_4 \)
     3. \( \text{CO}_2 \)
     4. \( \text{H}_2\text{O} \)
142. Shape of molecules is decided by:
     1. Sigma bond
     2. \( \pi \)-bond
     3. Both sigma and \( \pi \)-bonds
     4. Neither sigma nor \( \pi \)-bonds
143. The shape of carbon dioxide is
     1. Pyramidal
     2. Tetrahedral
     3. Planar
     4. linear
144. The correct ionic radii order is:
     1. \( \text{N}^{3-} > \text{O}^{2-} > \text{F}^- > \text{Na}^+ > \text{Mg}^{2+} > \text{Al}^{3+} \)
     2. \( \text{N}^{3-} > \text{Na}^+ > \text{O}^{2-} > \text{F}^- > \text{Mg}^{2+} > \text{Al}^{3+} \)
     3. \( \text{Na}^+ > \text{O}^{2-} > \text{N}^{3-} > \text{F}^- > \text{Mg}^{2+} > \text{Al}^{3+} \)
     4. \( \text{O}^{2-} > \text{F}^- > \text{Na}^+ > \text{N}^{3-} > \text{Mg}^{2+} > \text{Al}^{3+} \)
145. Which is not linear?
     1. \( \text{CO}_2 \)
     2. HCN
     3. \( \text{C}_2\text{H}_2 \)
     4. \( \text{H}_2\text{O} \)
146. Hybridisation of oxygen in diethyl ether is
     1. Sp
     2. \( sp^2 \)
     3. \( sp^3 \)
     4. \( sp^3d \)
147. What is the effect of more electronegative atom on the strength of ionic bond?
     1. Increases
     2. Decreases
     3. Remains the same
     4. None of these
148. Which of the following two are isostructural?
     1. \( \text{XeF}_2, \text{IF}_2^- \)
     2. \( \text{NH}_3, \text{BF}_3 \)
     3. \( \text{CO}_3^{2-}, \text{SO}_3^{2-} \)
     4. \( \text{PCl}_5, \text{ICl}_5 \)
149. \( \text{NF}_3 \) is:
     1. Non-polar compound
     2. Electrovalent compound
     3. Having low value of dipole moment than \( \text{NH}_3 \)
     4. Having more dipole moment than \( \text{NH}_3 \)
150. Molecular size of ICl and \( \text{Br}_2 \) is nearly same, but boiling point of ICl is about 40°C higher than \( \text{Br}_2 \). This might be due to:
     1. I—Cl bond is stronger than Br—Br bond
     2. Ionisation energy of I < ionisation energy of Br
     3. ICl is polar where as \( \text{Br}_2 \) is non-polar
     4. The size of I > size of Br