Thermodynamics Test

Question 1
4 / -1

Specific heat of iron at 25°C and 1.00 bar is

A
0.4454 JK^-1 g^-1

B
24.942 JK^-1 mol^-1

C
0.1071 cal K^-1 g^-1

D
All are correct

Question 2
4 / -1

A rather soft, silvery metal was observed to have a specific heat of 0.225 cal K^-1g^-1. Thus, metal is

A
Na

B
Mg

C
Al

D
Fe

Question 3
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Specific heat of water is 4.184 JK^-1g^-1, Rise in temperature when 1 kJ of heat is absorbed by 2 moles of H₂O is

A
119.5^o

B
0.37^o

C
0.12^o

D
6.64^o

Question 4
4 / -1

The amount of the heat released when 20 ml 0.5 M NaOH is mixed with 100 ml 0.1 M HCl is x kJ. The heat of neutralization is

A
– 100 x kJ/mol

B
– 50 x kJ/mol

C
+ 100 x kJ/mol

D
+50 x kJ/mol

Question 5
4 / -1

The heat capacity ratio, r was determined for cyanogen as 1.177. Thus, C_p for this gas is

A
55.3 JK^-1 mol^-1

B
33.26 JK^-1 mol^-1

C
8.314 JK^-1 mol^-1

D
24.94 JK^-1 mol^-1

Question 6
4 / -1

Assuming the composition of air to be X (N₂) = 0.80, X (O₂) = 0.18 and X (CO₂) = 0.02, molar heat capacity of air at constant pressure is

A
3.50R

B
4.00R

C
2.50R

D
3.51R

Question 7
4 / -1

Latent heat of fusion of ice is 6.02 kJ mol^-1. The heat capacity of water is 4.18 Jg^-1K^-1. 500 g of liquid water is to be cooled from 20°C to 0°C . Number of ice cubes (each of one mole) required is

A
1

B
7

C
14

D
125

Question 8
4 / -1

Sulphur (2.56 g) is burned in a constant volume calorimeter with excess O₂(g). The temperature increases from 21.25°C to 26.72°C . The bomb has a heat capacity of 923 JK^-1. Calorimeter contains 815 g of water. Thus, change in internal energy per mole of SO₂ formed for the reaction is
(specific heat of water is 4.184 JK^-1g^-1.)

A
- 296.27 kJ

B
+ 296.27 kJ

C
- 2370.13 kJ

D
+ 2370.13 kJ

Question 9
4 / -1

This sectionis based on statement I and Statement II. Select the correct answer from the code given below.

Q.

Statement I : C_v value of helium (He) is always 3/2R but C_v value of hydrogen (H₂) is 3/2R at low temperature, 5/2R at moderate temperature and more than 5/2R at higher temperature.

Statement II : At lower temperature, only translational degree of freedom contributes to heat capacity while at higher temperature, rotational and vibrational degrees of freedom also contribute to heat capacity.

A
Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I

B
Both Statement I and Statement II are correct and Statement II is not the correct explanation of Statement I

C
Statement I is correct but Statement II is incorrect

D
Statement II is correct but Statement I is incorrect

Question 10
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On which of the following factors the enthalpy change of a reaction is NOT dependent?

A
Nature of reactants and products

B
Various intermediate reactions

C
State of reactants and products

D
Enthalpy of reactants and products

Question 11
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In an endothermic reaction, the value of ΔH is always

A
Constant

B
< 0

C
> 0

D
= 0

Question 12
4 / -1

Direction (Q. Nos. 12 - 14) This section contains 3 questions. when worked out will result in an integer from 0 to 9 (both inclusive).

Q. An 88.5 g piece of iron whose temperature is 352.0 K is placed in a beaker containing 244 g of water at 292.0 K. When thermal equilibrium is reached, what is the change in the temperature of water?
Specific heat of water and iron are (4.184 Jg^-1 K^-1) and (0.449 Jg^-1 K^-1), respectively.

A
2

B
3

C
4

D
5

Question 13
4 / -1

The heat capacity of a calorimeter (commonly called the calorimeter constant) was determined by heating the calorimeter and its content using an electrical heater. If ΔT = 1.221 K as 1.25 A of electricity at 3.26 V was passed through the heater immersed in 137.5 g of water in the calorimeter for 175 s, determine the calorimeter constant (in JK^-1). (Specific heat of water at constant pressure is 75.291 JK^-1 mol^-1).

A
7

B
5

C
6

D
9

Question 14
4 / -1

In a constant volume calorimeter, 3.5 g of a gas (molar mass = 28 g mol^-1) was burnt in excess oxygen at 298.0 K. The temperature of the calorimeter was found to increase from 298.0 K to 298.45 K due to oxidation of the gas. Given that the heat capacity of the calorimeter is 2.5 kJ K^-1, the numerical value of the heat given out in kJ mol^-1 is

[IIT JEE 2009]

A
9

B
8

C
6

D
3

Question 15
4 / -1

Boiling point of ethanol (C₂H₅OH) = 78.29°C
Specific heat of ethanol = 2.44 J^-1K^-1
Enthalpy of vaporisation = 855 Jg^-1

Q. Energy required (in kJ) for the following change is

A
997.23 KJ

B
142.23 KJ

C
3.092 KJ

D
21.68 KJ

Question 16
4 / -1

Boiling point of ethanol (C₂H₅OH) = 78.29°C
Specific heat of ethanol = 2.44 J^-1K^-1
Enthalpy of vaporisation = 855 Jg^-1

Q. Energy required (in kJ) for the following change is

A
422.23 KJ

B
997.23 KJ

C
855.0 KJ

D
1139.46 KJ

Question 17
4 / -1

Choice the correct combination of elements and column I and coloumn II are given as option (a), (b), (c) and (d), out of which ONE option is correct.

Q. According to the classical equipartition of energy theory, the contributions to the molar heat capacity at constant volume are for each degree of translational freedom, for each degree of rotational freedom and (R) for each degree of translational freedom. Match the species in Column I with the values of molar heat capacity (C_p or C_V) in Column II and select answer from codes given below the table.

A
a

B
b

C
c

D
d

Submit Test

Thermodynamics ...

Question 1

0.4454 JK-1 g-1

24.942 JK-1 mol-1

0.1071 cal K-1 g-1

All are correct

Question 2

Na

Mg

Al

Fe

Question 3

119.5o

0.37o

0.12o

6.64o

Question 4

– 100 x kJ/mol

– 50 x kJ/mol

+ 100 x kJ/mol

+50 x kJ/mol

Question 5

55.3 JK-1 mol-1

33.26 JK-1 mol-1

8.314 JK-1 mol-1

24.94 JK-1 mol-1

Question 6

3.50R

4.00R

2.50R

3.51R

Question 7

1

7

14

125

Question 8

- 296.27 kJ

+ 296.27 kJ

- 2370.13 kJ

+ 2370.13 kJ

Question 9

Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I

Both Statement I and Statement II are correct and Statement II is not the correct explanation of Statement I

Statement I is correct but Statement II is incorrect

Statement II is correct but Statement I is incorrect

Question 10

Nature of reactants and products

Various intermediate reactions

State of reactants and products

Enthalpy of reactants and products

Question 11

Constant

< 0

> 0

= 0

Question 12

2

3

4

5

Question 13

7

5

6

9

Question 14

9

8

6

3

Question 15

997.23 KJ

142.23 KJ

3.092 KJ

21.68 KJ

Question 16

422.23 KJ

997.23 KJ

855.0 KJ

0.4454 JK^-1 g^-1

24.942 JK^-1 mol^-1

0.1071 cal K^-1 g^-1

119.5^o

0.37^o

0.12^o

6.64^o

55.3 JK^-1 mol^-1

33.26 JK^-1 mol^-1

8.314 JK^-1 mol^-1

24.94 JK^-1 mol^-1