Chemical Bonding & Molecular Structure Practice Questions - DPP for JEE

 Page 1


PART-I (Single Correct MCQs)
1. Which of the following has the highest dipole moment?
(a)
(b)
(c)
Page 2


PART-I (Single Correct MCQs)
1. Which of the following has the highest dipole moment?
(a)
(b)
(c)
(d)
2. In compounds of type ECl
3
, where E = B, P, As or Bi, the angles Cl - E-
Cl for different E are in the order.
(a) B > P = As = Bi
(b) B > P > As > Bi
(c) B < P = As = Bi
(d) B < P < As < Bi
3. The electronegativity difference between N and F is greater than that
between N and H yet the dipole moment ofNH
3
 (1.5 D) is larger than
that of NF
3
 (0.2D). This is because
(a) in NH
3
 the atomic dipole and bond dipole are in the same direction
whereas in NF
3
 these are  in opposite directions.
(b) in NH
3
 as well as NF
3
 the atomic dipole and bond dipole are in opposite
directions.
(c) in NH
3
 the atomic dipole and bond dipole are in the opposite directions
whereas in NF
3
 these are in the same direction.
(d) in NH
3
 as well as in NF
3
 the atomic dipole and bond dipole are in the
same direction.
4. On changing N
2
 to , the dissociation energy of N–N bond ..... and on
changing O
2 
to
 
O
+
? 2
 the dissociation energy of O–O bond....
(a) increases, decreases
(b) decreases, increases
(c) decreases in both cases
(d) increases in both cases
5. Which of the two ions from the list given below have the geometry that
Page 3


PART-I (Single Correct MCQs)
1. Which of the following has the highest dipole moment?
(a)
(b)
(c)
(d)
2. In compounds of type ECl
3
, where E = B, P, As or Bi, the angles Cl - E-
Cl for different E are in the order.
(a) B > P = As = Bi
(b) B > P > As > Bi
(c) B < P = As = Bi
(d) B < P < As < Bi
3. The electronegativity difference between N and F is greater than that
between N and H yet the dipole moment ofNH
3
 (1.5 D) is larger than
that of NF
3
 (0.2D). This is because
(a) in NH
3
 the atomic dipole and bond dipole are in the same direction
whereas in NF
3
 these are  in opposite directions.
(b) in NH
3
 as well as NF
3
 the atomic dipole and bond dipole are in opposite
directions.
(c) in NH
3
 the atomic dipole and bond dipole are in the opposite directions
whereas in NF
3
 these are in the same direction.
(d) in NH
3
 as well as in NF
3
 the atomic dipole and bond dipole are in the
same direction.
4. On changing N
2
 to , the dissociation energy of N–N bond ..... and on
changing O
2 
to
 
O
+
? 2
 the dissociation energy of O–O bond....
(a) increases, decreases
(b) decreases, increases
(c) decreases in both cases
(d) increases in both cases
5. Which of the two ions from the list given below have the geometry that
is explained by the same hybridization of orbitals, NO
2
? –
, NO
3
? –
, NH
2
? –
,
NH
4
? +
, SCN
– 
?
(a) and 
(b) and 
(c) SCN
–
 and 
(d) and 
6. Which of the following pairs of ions are isoelectronic and isostructural
?
(a)
(b)
(c)
(d)
7. Which of the following is correct increasing order of lone pair of
electrons   on the central atom?
(a) IF
7
 < IF
5
 < ClF
3
 < XeF
2
(b) IF
7
 < XeF
2
 < ClF
2 
< IF
5
(c) IF
7
 < ClF
3
 < XeF
2
 < IF
5
(d) IF
7
 < XeF
2
 < IF
5 
< ClF
3
8. Consider the molecules CH
4
, NH
3
 and H
2
O. Which of the given
statements is false?
(a) The H–C–H bond angle in CH
4
, the H–N–H bond angle in NH
3
, and the
H–O–H bond angle in H
2
O are all greater than 90°.
(b) The H–O–H bond angle in H
2
O is larger than the H–C–H bond angle in
CH
4
.
(c) The H–O–H bond angle in H
2
O is smaller than the H–N–H bond angle
in NH
3
.
Page 4


PART-I (Single Correct MCQs)
1. Which of the following has the highest dipole moment?
(a)
(b)
(c)
(d)
2. In compounds of type ECl
3
, where E = B, P, As or Bi, the angles Cl - E-
Cl for different E are in the order.
(a) B > P = As = Bi
(b) B > P > As > Bi
(c) B < P = As = Bi
(d) B < P < As < Bi
3. The electronegativity difference between N and F is greater than that
between N and H yet the dipole moment ofNH
3
 (1.5 D) is larger than
that of NF
3
 (0.2D). This is because
(a) in NH
3
 the atomic dipole and bond dipole are in the same direction
whereas in NF
3
 these are  in opposite directions.
(b) in NH
3
 as well as NF
3
 the atomic dipole and bond dipole are in opposite
directions.
(c) in NH
3
 the atomic dipole and bond dipole are in the opposite directions
whereas in NF
3
 these are in the same direction.
(d) in NH
3
 as well as in NF
3
 the atomic dipole and bond dipole are in the
same direction.
4. On changing N
2
 to , the dissociation energy of N–N bond ..... and on
changing O
2 
to
 
O
+
? 2
 the dissociation energy of O–O bond....
(a) increases, decreases
(b) decreases, increases
(c) decreases in both cases
(d) increases in both cases
5. Which of the two ions from the list given below have the geometry that
is explained by the same hybridization of orbitals, NO
2
? –
, NO
3
? –
, NH
2
? –
,
NH
4
? +
, SCN
– 
?
(a) and 
(b) and 
(c) SCN
–
 and 
(d) and 
6. Which of the following pairs of ions are isoelectronic and isostructural
?
(a)
(b)
(c)
(d)
7. Which of the following is correct increasing order of lone pair of
electrons   on the central atom?
(a) IF
7
 < IF
5
 < ClF
3
 < XeF
2
(b) IF
7
 < XeF
2
 < ClF
2 
< IF
5
(c) IF
7
 < ClF
3
 < XeF
2
 < IF
5
(d) IF
7
 < XeF
2
 < IF
5 
< ClF
3
8. Consider the molecules CH
4
, NH
3
 and H
2
O. Which of the given
statements is false?
(a) The H–C–H bond angle in CH
4
, the H–N–H bond angle in NH
3
, and the
H–O–H bond angle in H
2
O are all greater than 90°.
(b) The H–O–H bond angle in H
2
O is larger than the H–C–H bond angle in
CH
4
.
(c) The H–O–H bond angle in H
2
O is smaller than the H–N–H bond angle
in NH
3
.
(d) The H–C–H bond angle in CH
4
 is larger than the H–N–H bond angle
in NH
3
.
9. In which of the following species the interatomic bond angle is 109°
28’?
(a) NH
3
, 
(b) , BF
3
(c) NH
3
, BF
4
(d) , BF
3
.
10. Hybridisation of the underline atom changes in:
(a) changes to 
(b) changes to H
3
O
+
(c) changes to 
(d) in all cases
11. The states of hybridization of boron and oxygen atoms in boric acid
(H
3
BO
3
) are respectively
(a) sp
3
 and sp
2
(b) sp
2
 and sp
3
(c) sp
2
 and sp
2
(d) sp
3
 and sp
3
12. Among the following ions, the p – d overlap could be present in
(a)
(b)
(c)
(d)
13. Which one of the following pairs of species have the same bond order?
Page 5


PART-I (Single Correct MCQs)
1. Which of the following has the highest dipole moment?
(a)
(b)
(c)
(d)
2. In compounds of type ECl
3
, where E = B, P, As or Bi, the angles Cl - E-
Cl for different E are in the order.
(a) B > P = As = Bi
(b) B > P > As > Bi
(c) B < P = As = Bi
(d) B < P < As < Bi
3. The electronegativity difference between N and F is greater than that
between N and H yet the dipole moment ofNH
3
 (1.5 D) is larger than
that of NF
3
 (0.2D). This is because
(a) in NH
3
 the atomic dipole and bond dipole are in the same direction
whereas in NF
3
 these are  in opposite directions.
(b) in NH
3
 as well as NF
3
 the atomic dipole and bond dipole are in opposite
directions.
(c) in NH
3
 the atomic dipole and bond dipole are in the opposite directions
whereas in NF
3
 these are in the same direction.
(d) in NH
3
 as well as in NF
3
 the atomic dipole and bond dipole are in the
same direction.
4. On changing N
2
 to , the dissociation energy of N–N bond ..... and on
changing O
2 
to
 
O
+
? 2
 the dissociation energy of O–O bond....
(a) increases, decreases
(b) decreases, increases
(c) decreases in both cases
(d) increases in both cases
5. Which of the two ions from the list given below have the geometry that
is explained by the same hybridization of orbitals, NO
2
? –
, NO
3
? –
, NH
2
? –
,
NH
4
? +
, SCN
– 
?
(a) and 
(b) and 
(c) SCN
–
 and 
(d) and 
6. Which of the following pairs of ions are isoelectronic and isostructural
?
(a)
(b)
(c)
(d)
7. Which of the following is correct increasing order of lone pair of
electrons   on the central atom?
(a) IF
7
 < IF
5
 < ClF
3
 < XeF
2
(b) IF
7
 < XeF
2
 < ClF
2 
< IF
5
(c) IF
7
 < ClF
3
 < XeF
2
 < IF
5
(d) IF
7
 < XeF
2
 < IF
5 
< ClF
3
8. Consider the molecules CH
4
, NH
3
 and H
2
O. Which of the given
statements is false?
(a) The H–C–H bond angle in CH
4
, the H–N–H bond angle in NH
3
, and the
H–O–H bond angle in H
2
O are all greater than 90°.
(b) The H–O–H bond angle in H
2
O is larger than the H–C–H bond angle in
CH
4
.
(c) The H–O–H bond angle in H
2
O is smaller than the H–N–H bond angle
in NH
3
.
(d) The H–C–H bond angle in CH
4
 is larger than the H–N–H bond angle
in NH
3
.
9. In which of the following species the interatomic bond angle is 109°
28’?
(a) NH
3
, 
(b) , BF
3
(c) NH
3
, BF
4
(d) , BF
3
.
10. Hybridisation of the underline atom changes in:
(a) changes to 
(b) changes to H
3
O
+
(c) changes to 
(d) in all cases
11. The states of hybridization of boron and oxygen atoms in boric acid
(H
3
BO
3
) are respectively
(a) sp
3
 and sp
2
(b) sp
2
 and sp
3
(c) sp
2
 and sp
2
(d) sp
3
 and sp
3
12. Among the following ions, the p – d overlap could be present in
(a)
(b)
(c)
(d)
13. Which one of the following pairs of species have the same bond order?
(a) CN
–
 and NO
+
(b) CN
–
 and CN
+
(c) and CN
–
(d) NO
+
 and CN
+
14. N
2
 and O
2
 are converted into monocations,  and respectively.
Which of the following statements is wrong?
(a) In , N - N bond weakens
(b) In , the O - O bond order increases
(c) In , paramagnetism decreases
(d) becomes diamagnetic
15. The bond dissociation energy of B – F in BF
3
 is 646 kJ mol
–1
 whereas
that of  C – F in CF
4
 is 515 kJ mol
–1
. The correct reason  for higher B – F
bond dissociation energy as compared to that of C – F is
(a) stronger s bond between B and F in BF
3
 as compared to that between C
and F in CF
4
.
(b) significant pp – pp interaction between B and F in BF
3
 whereas there is
no possibility of such interaction between C and F in CF
4
.
(c) lower degree of pp – pp interaction between B and F in BF
3
 than that
between C and F in CF
4
.
(d) smaller size of B– atom as compared to that of C– atom.
16. ortho-Nitrophenol is less soluble in water than p- and m- Nitrophenols
because :
(a) o-Nitrophenol is more volatile steam than those of m- and p-isomers.
(b) o-Nitrophenol shows intramolecular H-bonding.
(c) o-Nitrophenol shows intermolecular H-bonding.
(d) Melting point of o-Nitrophenol is lower than those of m- and p-
isomers.
17. Amongst LiCl, RbCl, BeCl
2
 and MgCl
2
 the compounds with the