\(\underset {-10.7 \mathrm{JK}^{-1}{mol}^{-1}} {\mathrm{H}_{(a q)}^{+}+\mathrm{OH^{-}}_{(a q)}} \rightarrow \underset {+70 \mathrm{JK}^{-1} \mathrm{~mol}^{-1} } {\mathrm{H}_{2} \mathrm{O}_{(l)}} ~~ \mathrm{S}^{\circ}(298 \mathrm{~K})\)

Standard entropy change for the above reaction is:

1. 60.3 JK-1 mol-1

2. 80.7 JK-1 mol-1

3. -70 JK-1 mol-1

4. +10.7 JK-1 mol-1

Subtopic:  Spontaneity & Entropy |
 79%
Level 2: 60%+
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Which of the following thermodynamic quantities is an outcome of the second law of thermodynamics?

1. Work 2. Enthalpy
3. Internal energy 4. Entropy
Subtopic:  Spontaneity & Entropy |
 78%
Level 2: 60%+
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For the reaction, 2Cl(g)  Cl2(g), the correct option is:
1. \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) 2. \(\Delta_{\mathrm{r}} \mathrm{H}<0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0 \)
3. \(\Delta_{\mathrm{r}} \mathrm{H}<0 \) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) 4. \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0\)
Subtopic:  Enthalpy & Internal energy | Spontaneity & Entropy |
 61%
Level 2: 60%+
NEET - 2020
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Consider the following reaction:
2A (g) + B (g) → 2D (g)
\(ΔU^⊖\)=−10 \(kJ mol^{−1}\) and \(ΔS^⊖\)=−44 \(J K^{−1}\) at 298 K.

Identify the correct option with \(ΔG^⊖\) for the reaction and spontaneity of the reaction at 298 K.
(Given : R=\(8.31 ~J mol^{−1} K^{−1}\))
1. −1.635 kJ mol−1, spontaneous
2. +0.63568 kJ mol−1, non-spontaneous
3. −0.63568 kJ mol−1, spontaneous
4. +1.635 kJ mol−1, non-spontaneous
Subtopic:  Spontaneity & Entropy | Gibbs Energy Change |
 56%
Level 3: 35%-60%
NEET - 2026
Please attempt this question first.
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Please attempt this question first.

1 mole of an ideal gas at 25°C is subjected to expand reversibly ten times of its initial volume.
The change in entropy of expansion is:

1. 19.15 JK–1mol–1                         

2. 16.15 JK–1mol–1

3. 22.15 JK–1mol–1                         

4. None of the above

Subtopic:  Spontaneity & Entropy |
 68%
Level 2: 60%+
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Entropy decreases in which of the following reactions?

1. Boiling of egg

2. Combustion of benzene at 127°C

3. Stretching of rubber band

4. Dissolution of sugar in water

Subtopic:  Spontaneity & Entropy |
 64%
Level 2: 60%+
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The unit of entropy is -

1. J mol–1

2. JK mol–1

3. J mol–1 K–1

4. J–1 K–1 mol–1

Subtopic:  Spontaneity & Entropy |
 85%
Level 1: 80%+
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The molar entropy of the vapourization of acetic acid is\(14.4~ \mathrm{cal}~ \mathrm{K}^{-1} \mathrm{~mol}^{-1}\) at its boiling point 118C. The latent heat of vapourization of acetic acid is-

1. \(49 ~\mathrm{cal}~ \mathrm{g}^{-1} \) 2. \(64 ~\mathrm{cal}~ \mathrm{g}^{-1} \)
3. \(94 ~\mathrm{cal}~ \mathrm{g}^{-1} \) 4. \(84 ~\mathrm{cal}~ \mathrm{g}^{-1} \)
Subtopic:  Spontaneity & Entropy |
 62%
Level 2: 60%+
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Entropy decreases during:

1. Crystallization of sucrose from solution

2. Rusting of iron

3. Melting of ice

4. Vaporization of camphor

Subtopic:  Spontaneity & Entropy |
 85%
Level 1: 80%+
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Find the process showing negative entropy change:

1. Bromine (l)Bromine(g)

2. C(s) + H2O(g) CO(g) + H2(g)

3. N2(g,10 atm)N2(g,1 atm) 

4. Fe ( 1mol, 400 K)  Fe( 1mol, 300 K)

Subtopic:  Spontaneity & Entropy |
 73%
Level 2: 60%+
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