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Jeneeta Eliza John
Subject: Chemistry
, asked on 2/5/18
Explain qno.55 Ans(2)
55. A closed adiabatic system will be
(1) Isolated (2) Non - isolated
(3) Open system (4) Both (2) & (3)
Answer
0
Jeneeta Eliza John
Subject: Chemistry
, asked on 2/5/18
Explain qno.79 Ans(3):
79. The pressure of CO
2
at 27
o
C for the reaction CaCO
3
(S)
⇌
CaO(s) + CO
2
(g) is 10 atm. If the number of moles of CO
2
is doubled keeping volume and temperature constant. The pressure of CO
2
will become .
(1) 20 atm
(2) 15 atm
(3) Remain same
(4) Data insufficient.
Answer
0
Jeneeta Eliza John
Subject: Chemistry
, asked on 2/5/18
If C(g) → C(s); ΔH = – 100 kJ/mole and ΔH
f
(CO
2
) = – 400 kJ/mole, then find out the value of B.E
O = O
, if B.E
C = O
= 600 kJ/mole.
(1) 100 kJ (2) 300 kJ (3) 500 kJ (4) 700 kJ
Answer
0
Jeneeta Eliza John
Subject: Chemistry
, asked on 2/5/18
Explain who.69. Ans(3):
69. Which of the following reaction can be used to calculate the value of
△
H
f
o
of the product ?
1
1
2
H
2
g
+
1
2
Br
2
g
→
HBr
g
2
C
diamond
+
O
2
g
→
CO
2
g
3
P
4
White
+
3
O
2
g
→
P
4
O
6
s
4
CO
g
+
1
2
O
2
g
→
CO
2
g
Answer
1
Jeneeta Eliza John
Subject: Chemistry
, asked on 2/5/18
Explain qno.52. Ans(2)
Answer
0
Nithyashrri Saravanan
Subject: Chemistry
, asked on 1/5/18
11. One mole of an anhydrous salt AB dissolves in water with the evolution of 21.0 J mol
-1
of heat. If the heat of hydration of AB is -29.4 J mol
-1
, then the heat of dissociation of hydrated salt AB is
a
)
50
.
4
J
m
o
l
-
1
b
)
8
.
4
J
m
o
l
-
1
c
)
-
50
.
4
J
m
o
l
-
1
d
)
-
8
.
4
J
m
o
l
-
1
Answer
1
Hermoine
Subject: Chemistry
, asked on 12/4/18
Please help fast
Q. At 27
°
C two moles of an ideal monoatomic gas occupies a volume V. The gas expands adiabatically to a volume 2 V. Calculate: (a) the final temperature of the gas, (b) the change in internal energy, (c) the work
done by the gas
ANS (a) 189 K, (b) - 2767 J. (c) 2767
Answer
1
Hermoine
Subject: Chemistry
, asked on 3/4/18
A sample of 4.0 mole 0 2 is originally confined in 20 L at 270 K is subjected to reversible adiabatic expansion against a constant pressure until the volume has been increased by a factor 3.0. Calculate q, W, dT, dE, dH and final pressure. Assume Cp /Cv = 1.40 for 02 gas
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 2/4/18
Solve
49.
If bond energy of C
≡
C, C-H, O=O, C=O & O-H bond is 800, 410, 500, 700 & 430 kJ / mol respectively, then calorific value (kJ/gm) of ethyne is
(1) 25.28
(2) 30.38
(3) 790
(4) 303
Answer
2
Aaradhya Kondawar
Subject: Chemistry
, asked on 2/4/18
Explain with reason.
47
.
F
o
r
w
h
i
c
h
o
f
t
h
e
f
o
l
l
o
w
i
n
g
p
r
o
c
e
s
s
∆
S
i
s
n
e
g
a
t
i
v
e
?
(
1
)
B
o
i
l
i
n
g
o
f
e
g
g
(
2
)
C
l
2
(
1
a
t
m
,
27
°
C
)
→
C
l
2
(
1
.
5
a
t
m
,
27
°
C
)
(
3
)
E
v
a
p
o
r
a
t
i
o
n
o
f
w
a
t
e
r
(
4
)
P
C
l
5
(
g
)
→
P
C
l
3
(
g
)
+
C
l
2
(
g
)
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 1/4/18
Solve this:
Q5. The COP of a refrigerator is 5 is kept in a room having temperature at 27
°
C temperature inside the refrigerator will be
(A) - 23
(B) - 27
(C) - 46
(D) - 54
Q6. The temperature of the gas before and after expansion
(A) T
before
> T
after
(B) T
before
< T
after
(C) T
before
= T
after
(D) needs more information
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
The enthalpy of solution of BaCl
2
(s) and BaCl
2
.2H
2
O(s) is –x kJ mol
–1
and y kJ mol
–1
respectively then enthalpy of hydration of BaCl
2
(s) to BaCl
2
.2H
2
O(s) is given by
(1) (x – y) kJ (2) (y – x) kJ (3) (x + y) kJ (4) –(x + y) kJ
Answer
4
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Q58 and Q59:
58. Which of the following is a spontaneous process takes place on initiation ?
(1) Dissolution of common salt in water.
(2) Reaction between methane and oxygen to form CO
4
and water.
(3) Evaporation of water in an open vessel.
(4) All of these.
59. Select the correct statement.
(1) During hydration the physical state of the sold does not change.
(2) During dissolution , the physical state of solid changes.
(3) Enthalpy of formation of an atom is nearly half of the bond dissociation energy of gaseous diatomic molecule.
(4) All of these.
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Solve this:
60. Which of the following is not zero in cyclic process ?
(1)
△
S (2)
△
U (3) W (4)
△
T
Answer
2
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
S
o
l
v
e
t
h
i
s
:
E
n
t
h
a
l
p
y
o
f
f
o
r
m
a
t
i
o
n
i
s
z
e
r
o
f
o
r
(
1
)
D
i
a
m
o
n
d
(
2
)
G
r
a
p
h
i
t
e
(
3
)
C
l
(
a
q
)
(
4
)
A
l
l
o
f
t
h
e
s
e
Answer
1
1
2
3
4
5
Next
What are you looking for?
55. A closed adiabatic system will be
(1) Isolated (2) Non - isolated
(3) Open system (4) Both (2) & (3)
79. The pressure of CO2 at 27oC for the reaction CaCO3(S) CaO(s) + CO2(g) is 10 atm. If the number of moles of CO2 is doubled keeping volume and temperature constant. The pressure of CO2 will become .
(1) 20 atm
(2) 15 atm
(3) Remain same
(4) Data insufficient.
(1) 100 kJ (2) 300 kJ (3) 500 kJ (4) 700 kJ
69. Which of the following reaction can be used to calculate the value of of the product ?
Q. At 27C two moles of an ideal monoatomic gas occupies a volume V. The gas expands adiabatically to a volume 2 V. Calculate: (a) the final temperature of the gas, (b) the change in internal energy, (c) the work
done by the gas
ANS (a) 189 K, (b) - 2767 J. (c) 2767
49. If bond energy of CC, C-H, O=O, C=O & O-H bond is 800, 410, 500, 700 & 430 kJ / mol respectively, then calorific value (kJ/gm) of ethyne is
(1) 25.28
(2) 30.38
(3) 790
(4) 303
Q5. The COP of a refrigerator is 5 is kept in a room having temperature at 27 C temperature inside the refrigerator will be
(A) - 23
(B) - 27
(C) - 46
(D) - 54
Q6. The temperature of the gas before and after expansion
(A) Tbefore > Tafter
(B) Tbefore < Tafter
(C) Tbefore = Tafter
(D) needs more information
(1) (x – y) kJ (2) (y – x) kJ (3) (x + y) kJ (4) –(x + y) kJ
58. Which of the following is a spontaneous process takes place on initiation ?
(1) Dissolution of common salt in water.
(2) Reaction between methane and oxygen to form CO4 and water.
(3) Evaporation of water in an open vessel.
(4) All of these.
59. Select the correct statement.
(1) During hydration the physical state of the sold does not change.
(2) During dissolution , the physical state of solid changes.
(3) Enthalpy of formation of an atom is nearly half of the bond dissociation energy of gaseous diatomic molecule.
(4) All of these.
60. Which of the following is not zero in cyclic process ?
(1) S (2) U (3) W (4) T