For which of the following equations, \(\Delta H > \Delta E \) ? 

\(1.~~\mathrm{N}_{2}(g)+3 \mathrm{H}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{NH}_{3}(\mathrm{g})\\ \\ 2.~~\mathrm{H}_{2}(g)+\frac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \longrightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{l})\\ \\ 3.~~\mathrm{PCl}_{5}(g) \rightarrow \mathrm{PCl}_{3}(g)+\mathrm{Cl}_{2}(g)\\ 4.~~\mathrm{H}_{2}(\mathrm{~g})+\mathrm{I}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{HI}(\mathrm{g}) \)
Subtopic:  Enthalpy & Internal energy |
 79%
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If water vapour is assumed to be a perfect gas, molar enthalpy change for vapourisation of 1 mol of water at 1 bar and 100°C is 41kJ mol–1. The internal energy change, when 1 mol of water is vapourised at 1 bar pressure and 100°C is:

1. 35.5 kJ mol–1

2. 37.9 kJ mol–1

3.  41 kJ mol–1

4. 44.2 kJ mol–1

Subtopic:  Enthalpy & Internal energy |
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A swimmer coming out from a pool is covered with a film of water weighing about 18g. The internal energy of vaporization at 298K. is-

vap H for water at 298K= 44.01kJ mol–1

1. 38.63 kJ
2. 43.82 J
3. 41.53 kJ
4. 40.33 J

Subtopic:  Enthalpy & Internal energy |
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Assertion (A): The increase in internal energy \((\Delta E ) \) for the vapourisation of one mole of water at 1 atm and 373 K is zero.
Reason (R): For all isothermal processes, \(\Delta E = 0 \).
 
1.  Both (A) and (R) are True and (R) is the correct explanation of (A).
2.  Both (A) and (R) are True but (R) is not the correct explanation of (A).
3.  (A) is True and (R) is False.
4.  (A) and (R) both are False.
Subtopic:  Enthalpy & Internal energy |
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The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0 °C is:

1. 10.52 cal/(mol K)

2. 21.04 cal/(mol K)

3. 5.260 cal/(mol K)

4. 0.526 cal/(mol K)

Subtopic:  Enthalpy & Internal energy |
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