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1. The internal energy change when a system goes
from state A to B is 40 kJ/mole. If the system goes
from A to B by a reversible path and returns to
state A by an irreversible path what would be the
net change in internal energy
[CBSE PMT 2003]
(a) 40 kJ (b) > 0 kJ
(c) < 40 kJ (d) Zero
2. The correct relationship is [DPMT 2002]
(a) H P V V (b) H nRT E
(c) E nRT P (d) None of these
3. For () 3
CaCO s ⇌ ( ) ()
2
CaO s CO g at C
o
H 176 kJ mol , then E is [BVP 2003]
(a) 180 kJ (b) 186.4 kJ
(c) 165.6 kJ (d) 160 kJ
4. Values of H and S for five different reactions
are given below.
Reaction ( )
1
HkJmol ( )
1 1
SJK mol
I
II
III
IV
V
On the basis of these values predict which one of
these will be spontaneous at all tempeature
[Kerala PMT 2004; KCET 1988,90]
(a) Reaction I (b) Reaction II
(c) Reaction III (d) Reaction IV
(e) Reaction V
5. Molar heat capacity of water in equilibrium with
ice at constant pressure is [IIT JEE 1997]
(a) Zero (b) Infinity()
(c)
1 1
- 45
kJK mol (d)
1
- 48
J K
6. Internal energy does not include
[AIIMS 1999; CPMT 2000]
(a) Nuclear energy
(b) Rotational energy
(c) Vibrational energy
(d) Energy arising by gravitational pull
7. Two moles of an ideal gas expand spontaneously
into a vacuum. The work done is [AMU 2000]
(a) 2 Joule (b) 4 Joule
(c) Zero (d) Infinite
8. Heat exchanged in a chemical reaction at constant
temperature and constant pressure is called as
[BHU 1998; Pb. PET 2000; MP PET 2002]
(a) Internal energy (b) Enthalpy
(c) Entropy (d) Free energy
9. Which of the following statements is true [KCET 2002]
(a) E
is always greater than H
(b) E is always less than H
(c) E
may be lesser or greater or equal to H
(d) E is always proportional to H
10. Mass and energy are conserved is demonstrated
by
[MH CET 2002]
(a) First law of thermodynamics
(b) Law of conservation of energy
(c) Law of conservation of mass
(d) Modified form of I
st
law of thermodynamics
11. The enthalpy of the reaction,
() ()
2
1
( )
2 2 2
H g O g HOg is
1
H
and that of
() ()
2
1
( )
2 2 2
H g O g HOl is
2
H. Then [KCET 2004]
(a)
1 2
H H (b) 0
1 2
H H
(c)
1 2
H H (d)
1 2
H H
12. A reaction occurs spontaneously if
[MP PET 2002; CBSE PMT 2005]
(a) T S H and both H and S are +ve
(b) T S H and both H and S are +ve
(c) T S H and both H and S are +ve
(d) T S H and H is +ve and S is – ve
13. Which expression is correct for the work done in
adiabatic reversible expansion of an ideal gas [AMU 2002]
(a)
1
2
ln
V
V
W nRT (b)
1
2
ln
T
T
W n
e
(c) W P V (d)
2
1
W PdV
14. If an endothermic reaction is non-spontaneous at
freezing point of water and becomes feasible at
its boiling point, then
[AIEEE 2002]
(a)
H
is
ve
,
S
is + ve
(b)
H
and
S
both are + ve
(c)
H and
S
both are – ve
(d)
H
is + ve ,
S
is – ve
15. What is the entropy change (in
1 1
JK mol
) when
one mole of ice is converted into water at
C
o
0
(The enthalpy change for the conversion of ice to
liquid water is 6.0 kJ
1
mol
at
C
o
0
) [CBSE PMT 2003]
(a) 21.98 (b) 20.
(c) 2.013 (d) 2.
16. One mole of
NaCl ( s ) on melting absorbed
- 5 kJ
of heat and its entropy is increased by
1
- 8
JK
The melting point of
NaCl is [DPMT 2004]
(a) 1059 K (b) 30.5 K
(c) 28.8 K (d) 28800 K
17. The enthalpy change
( H )
for the process
2 4
N H g Ng Hg
in
1
1724
KJ mol
. If the
bond energy of
N H
bond in ammonia is
1
391
KJ mol
. What is the bond energy of
N N
bond is
2 4
NH
[MP PMT 2004]
(a)
1
160
KJ mol (b)
1
391
KJ mol
(c)
1
1173
KJ mol (d)
1
320
KJ mol
18. Liquid ammonia is used in refrigeration because
of its
[DCE 2003]
(a) High dipole moment
(b) High heat of vaporisation
(c) High basicity
(d) All of these
19. A cylinder of gas supplied by Bharat Petroleum is
assumed to contain
14 kg
of butane. It a normal
family requires
20 , 000 kJ
of energy per day for
cooking, butane gas in the cylinder last for ….
Days [Kerala PMT 2004]
c
H of C H 2658 KJpermole
4 10
(a) 15 days (b) 20 days
(c) 50 days (d) 40 days
(e) 32 days
20. The heat of neutralization of HCl by NaOH under
certain condition is – 55.9 kJ and that of HCN by
NaOH
is – 12.1 kJ. the heat of ionization of HCN
is [MP PET 2001]
(a)
1
- 0
kJmol (b)
1
- 8
kJmol
(c)
1
- 0
kJ mol (d)
1
- 8
kJ mol
21. Equilibrium constant of a reaction is related to
[AIIMS 1991]
(a) Standard free energy change
o
G
(b) Free energy change G
(c) Temperature T
(d) None
22. The standard Gibbs free energy change
o
G is
related to equilibrium constant
p
K as [MP PET/PMT 1998]
(a)
o
p
K RT ln G (b)
o
G
p
RT
e
K
(c)
RT
G
K
o
p
(d)
RT
G
p
o
K e
23. The standard enthalpy or the decomposition of
2 5
NO to
2
NO is 58.04 kJ and standard entropy of
this reaction is 176. 7 J / K. The standard free
energy change for this reaction at C
o
25 is [DCE 2004]
(a) – 5.38 kJ (b) 5.38 kJ
(c) 5.38 kJ (d) – 538 kJ
24. For the equilibrium ()
2
HOl ⇌ ()
2
HOg at 1 atm and
298 K
[AIIMS 2004]
(a) Standard free energy change is equal to zero
o
G
14000 gm
gives 14000 45. 8
641200 KJ
Family need 20 , 000 KJ / day
So gas full fill the requirement for
- 06 days
20. (d) 21. (a) G 2. 303 log k.
o
22. (d)
G RT
p
o
K e
/
23. (d) 24. (b) For reaction ()
2
HOl ⇌ ()
2
HOg
n 1 means positive
so when n is positive then G 0.
25. (c) G H T S
G 0 at equilibrium
H T S or 30. 56 T 0. 066
T 463 K.
