Entropy decreases during:

1. Crystallization of sucrose from solution

2. Rusting of iron

3. Melting of ice

4. Vaporization of camphor

Given the reaction:
\(2 \mathrm{Cl}(\mathrm{~g}) \rightarrow \mathrm{Cl}_2(\mathrm{~g})\)
What are the values of \(∆\mathrm{H}\) and \(∆\mathrm{S}\), respectively?

1. \(\Delta \mathrm{H}=0, \Delta \mathrm{~S}=-\mathrm{ve}\)
2. \(\Delta \mathrm{H}=0, \Delta \mathrm{~S}=0\)
3. \(\Delta \mathrm{H}=-\mathrm{ve}, \Delta \mathrm{~S}=-\mathrm{ve}\)
4. \(\Delta \mathrm{H}=+\mathrm{ve}, \Delta \mathrm{~S}=+\mathrm{ve}\)

For a sample of a perfect gas when its pressure is changed isothermally from P_i to P_f, the entropy change is given by:

1. $∆\mathrm{s}=\mathrm{nR}$ $\mathrm{In}$ $\left(\frac{{\mathrm{p}}_{\mathrm{f}}}{{\mathrm{p}}_{\mathrm{i}}}\right)$

2. $∆\mathrm{s}=\mathrm{nR}$ $\mathrm{In}$ $\left(\frac{{\mathrm{p}}_{\mathrm{i}}}{{\mathrm{p}}_{\mathrm{f}}}\right)$

3. $∆\mathrm{s}=\mathrm{nRT}$ $\mathrm{In}$ $\left(\frac{{\mathrm{p}}_{\mathrm{f}}}{{\mathrm{p}}_{\mathrm{i}}}\right)$

4. $∆\mathrm{s}=\mathrm{RT}$ $\mathrm{In}$ $\left(\frac{{\mathrm{p}}_{\mathrm{i}}}{{\mathrm{p}}_{\mathrm{f}}}\right)$

For irreversible expansion of an ideal gas under isothermal condition, the correct option is :

1. $∆\mathrm{U}=0, ∆{\mathrm{S}}_{\mathrm{total}}\ne 0$

2. $∆\mathrm{U}\ne 0, ∆{\mathrm{S}}_{\mathrm{total}}=0$

3. $∆\mathrm{U}=0, ∆{\mathrm{S}}_{\mathrm{total}}=0$

4. $∆\mathrm{U}\ne 0, ∆{\mathrm{S}}_{\mathrm{total}}\ne 0$

For the reaction, 2Cl(g) $\to$ Cl₂(g), the correct option is:

1. ${∆}_{\mathrm{r}}\mathrm{H}>0 \mathrm{and} {∆}_{\mathrm{r}}\mathrm{S}<0$

2. ${∆}_{\mathrm{r}}\mathrm{H}<0 \mathrm{and} {∆}_{\mathrm{r}}\mathrm{S}>0$

3. ${∆}_{\mathrm{r}}\mathrm{H}<0 \mathrm{and} {∆}_{\mathrm{r}}\mathrm{S}<0$

4. ${∆}_{\mathrm{r}}\mathrm{H}>0 \mathrm{and} {∆}_{\mathrm{r}}\mathrm{S}>0$

Match the following parameters with a description for spontaneity.

Codes:

Match the following process with entropy change:

Codes:

If for a certain reaction ${∆}_{r}H$ is 30 kJ mol^–1 at 450 K, the value of ${∆}_{r}S$ (in JK^–1 mol^–1) for which the same reaction will be spontaneous at the same temperature is:

The enthalpy and entropy change for the reaction :

Br₂ (l) + Cl₂ (g)$\to$ 2BrCl (g)

are 30 kJ mol^-1 and 105 J K^-1 mol^-1 respectively.

The temperature at which the reaction will be in equilibrium is :

1 mole of an ideal gas at 25$°\mathrm{C}$ 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