The pair of isochoric among the transformation of state is:

1. K to L and L to M

2. L to M and N to K

3. L to M and M to N

4. M to N and N to K

Subtopic:  Classification of System, Extensive & Intensive Properties |
 89%
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Given, the following reaction:

N2H4(g)          N2H2(g)+H2(g);
Given:  ∆ H= 109 kJ/mol

B.E. of (N-N) = 163 kJ/mol

B.E. of (N-H) = 391 kJ/mol

B.E. of (H-H) = 436 kJ/mol

Calculate the bond enthalpy of N = N.

1. 182 kJ/mol

2. 400 kJ/mol

3. 300 kJ/mol

4. 218 kJ/mol

Subtopic:  Thermochemistry |
 72%
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Thermodynamics is not concerned about-

1. Energy changes involved in a chemical reaction
2. The extent to which a chemical reaction proceeds
3. The rate at which a reaction proceeds
4. The feasibility of a chemical reaction
Subtopic:  Thermodynamics' Properties and process |
 71%
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Reversible expansion of an ideal gas under isothermal and adiabatic conditions are as shown in the figure:

 

ABIsothermal expansion

ACAdiabatic expansion

Which of the following options is not correct?

1. Sisothermal>Sadiabatic

2. TA=TB

3. Wisothermal>Wadiabatic

4. TC>TA

Subtopic:  2nd & 3rd Law of Thermodynamics |
 53%
From NCERT
NEET - 2019
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An ideal gas expands isothermally from 10-3m3 to 10-2 m3 at 300 K against a constant pressure of 105 Nm-2. The work done by  the gas is:

1. +270 kJ 2. –900 J
3. +900 kJ 4. –900 kJ
Subtopic:  First Law of Thermodynamics |
 70%
From NCERT
NEET - 2019
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If for a certain reaction rH is 30 kJ mol–1 at 450 K, the value of rS (in JK–1 mol–1) for which the same reaction will be spontaneous at the same temperature is:

1. 70

2. –33

3. 33

4. –70

Subtopic:  Spontaneity & Entropy |
 69%
From NCERT
NEET - 2020
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Identify the correct statement regarding entropy:

1. At absolute zero of temperature, the entropy of all crystalline substances is taken to be zero
2. At absolute zero of temperature, the entropy of a perfectly crystalline substance is +ve
3. At absolute zero of temperature, the entropy of a perfectly crystalline substance is taken to be zero
4. At 0 °C , the entropy of a perfectly crystalline substance is taken to be zero
Subtopic:  2nd & 3rd Law of Thermodynamics |
 64%
From NCERT
AIPMT - 1998
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When 1 mol gas is heated at constant volume, the temperature is raised from 298 to 308 K. Heat supplied to the gas is 500 J. The correct statement among the following is:
1.  q = w = 500 J, ∆U = 0
2.  q = ∆U = 500 J, w = 0
3.  q = w = 500 J, ∆U = 0
4.  ∆U = 0, q = w = – 500 J

Subtopic:  First Law of Thermodynamics |
 86%
From NCERT
AIPMT - 2001
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Consider the following reactions: 

(i) H+(aq) + OH-(aq) → H2O(l)
ΔH = -x1 kJmol-1
(ii) H2(g) + 1/2O2(g) → H2O(l)
ΔH = -x2 kJmol-1
(iii) CO2(g) + H2(g) → CO (g) + H2O(l)
ΔH = -x3 kJmol-1
(iv) C2H2(g) + 5/2O2(g) →  2CO+ H2O(l)
ΔH = -x4 kJmol-1


Enthalpy of formation of H2O(l) is :

1. -x3 kJ mol-1

2. -x4 kJ mol-1

3. -x1 kJ mol-1

4. -x2 kJ mol-1

Subtopic:  Thermochemistry |
 75%
From NCERT
AIPMT - 2007
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The heat of combustion of carbon to CO2 is –393.5 KJ/mol. The heat changed upon the formation of 35.2 g of CO2 from carbon and oxygen gas is:
1. –315 KJ
2. +315 KJ
3. –630 KJ
4. +630 KJ

Subtopic:  Thermochemistry |
 73%
From NCERT
NEET - 2015
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