Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is:

1. ${\mathrm{\Delta S}}_{\mathrm{system<mspace\; width="1em"></mspace>}}-{\mathrm{\Delta S}}_{\mathrm{surrounding<mspace\; width="1em"></mspace>}}>0$

2. ${\mathrm{\Delta S}}_{\mathrm{system<mspace\; width="1em"></mspace>}}>0\mathrm{<mspace\; width="1em"></mspace>only<mspace\; width="1em"></mspace>}$

3. ${\mathrm{\Delta S}}_{\mathrm{surroundings<mspace\; width="1em"></mspace>}}>\mathrm{0}$ $\mathrm{only}$

4. ${\mathrm{\Delta S}}_{\mathrm{system<mspace\; width="1em"></mspace>}}+{\mathrm{\Delta S}}_{\mathrm{surrounding<mspace\; width="1em"></mspace>}}>0$

The standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are –382.64 kJ mol^–1 and –145.6 JK^–1 mol^–1, respectively. Standard Gibbs energy change for the same reaction at 298 K is:

1. –339.3 kJ mol^–1

2. – 439.3 kJ mol^–1

3. –523.2 kJ mol^–1

4. –221.1 kJ mol^–1

The work done during the expansion of a gas from a volume of 4 dm³ to 6 dm³ against a constant external pressure of 3 atm is:

1. –608 J

2. +304 J

3. –304 J

4. –6.00 J 

$2Zn+O_2\to 2ZnO$ $$ $$ $$ $∆G°=-616$ $J$
$2Zn+S_2\to 2ZnS$ $$ $$ $$ $$ $∆G°=-293$ $J$
$S_2+2O_2\to 2S{O}_2$ $$ $$ $$ $$ $∆G°=-408J$

$∆G°$ for the following reaction is:

$2ZnS+3O_2\to 2ZnO+2S{O}_2$

At 27ºC latent heat of fusion of a compound is 2930 J/mol. Entropy change is:

1. 9.77 J/mol K

2. 10.77 J/mol K

3. 9.07 J/mol K

4. 0.977 J/mol K

For the reaction
C₂H₅OH(l) + 3O₂(g) →2CO₂(g) + 3H₂O(l) which one is true:

In a closed insulated container a liquid is stirred with a paddle to increase the temperature. The correct option regarding this among the following is:

1. ∆E = W ≠ 0, q = 0

2. ∆E = W = q ≠ 0

3. ∆E = 0, W = q ≠ 0

4. W = 0 , ∆E = q ≠ 0

2 mole of an ideal gas at 27ºC temp. is expanded reversibly from 2 lit. to 20 lit. Find entropy change (R = 2 cal/mol K): 

1. 92.1

2. 0

3. 4

4. 9.2

Heat of combustion ∆Hº for C(s), H₂(g) and CH₄(g) are – 94, – 68 and – 213 Kcal/mol. ∆Hº for C(s) + 2H₂(g) → CH₄ (g) is:

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 =0, w = 500 J, ∆U = 0
4.  ∆U = 0, q = w = – 500 J