The entropy change in the fusion of one mole of a solid melting at 27C is:
(the latent heat of fusion is 2930 J mol-1)
1. 9.77 JK-1mol-1
2. 19.73 JK-1mol-1
3. 2930 JK-1mol-1
4. 108.5 JK-1mol-1
1 mole of an ideal gas at 25 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
In the reaction, H and S both are positive. The condition under which the reaction would not be spontaneous is -
1. H>TS
2. S=H/T
3. H=TS
4. All of the above
Determine the enthalpy change for the specified reaction:
2H2O2(l) 2H2O(l) + O2(g).
(Given the heat of formation of H2O2(l) and H2O(l) are –188 and –286 kJ/mol respectively)
1. | –196 kJ/mol | 2. | +196 kJ/mol |
3. | +948 kJ/mol | 4. | –948 kJ/mol |
Entropy decreases in which of the following reactions?
1. Boiling of egg
2. Combustion of benzene at 127C
3. Stretching of rubber band
4. Dissolution of sugar in water
Equilibrium is represented by:
1. H = 0
2. GTotal = 0
3. STotal = 0
4. E = 0
Work done is maximum in -
1. Isobaric work
2. Isothermal work
3. Isochoric work
4. Adiabatic work
For exothermic reaction to be spontaneous (=negative) temperature must be -
1. | High | 2. | Zero |
3. | Constant | 4. | Low |
'The free energy change due to a reaction is zero when-
1. The reactants are initially mixed.
2. A catalyst is added
3. The system is at equilibrium
4. The reactants are completely consumed
For a given reaction, H =35.5 kJ mol-1 and S = 83.6JK-1 mol-1. The reaction is spontaneous at:
(Assume that H and S do not vary with temperature)
1. | T < 425 K | 2. | T > 425 K |
3. | All temperatures | 4. | T > 298 K |