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
'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
18 g of ice is converted into water at 0C and 1 atm. The entropy of H2O(s) and H2O(l) are 38.2 and 60 J K-1 mol-1 respectively. the enthalpy for this conversion will be
(1) 5951.4 J/mol
(2) 595.14 J/mol
(3) -595.14 J/mol
(4) None of these
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 |
The correct thermodynamic conditions for the spontaneous reaction at all temperatures is
For the reaction, X2O4(l) 2XO2(g)
U = 2.1 kcal, S = 20 cal K-1 at 300 K. Hence, G is
1. 2.7 kcal
2. -2.7 kcal
3. 9.3 kcal
4. -9.3 kcal
The values of H and S for the given reaction are 170 kJ and 170 JK–1, respectively.
\(\mathrm{C} \text { (graphite) }+\mathrm{CO}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}(\mathrm{g})\)
This reaction will be spontaneous at:
1. 710 K
2. 910 K
3. 1110 K
4. 510 K
Identify the correct statement for change of Gibbs energy for a system (Gsystem) at constant temperature and pressure:
(1) If Gsystem > 0, the process is spontaneous
(2) If Gsystem = 0, the system has attained equilibrium
(3) If Gsystem = 0, the system is still moving in a particular direction
(4) If Gsystem < 0, the process is not spontaneous
The enthalpy and entropy change for a chemical reaction are
–2.5 × 103 cal and 7.4 cal deg–1 respectively. Predict the reaction at 298 K is
1. Spontaneous
2. Reversible
3. Irreversible
4. Non-spontaneous
Which of the following is true for the reaction at 100°C and 1 atmosphere
1. ΔE = 0
2. ΔH = 0
3. ΔH = ΔE
4. ΔH = TΔS