According to the law, a perfect crystal's entropy is 0 at absolute zero, which is:

1. The first law               

2. Second law

3. Third law             

4. None of the above

At constant pressure and temperature, the direction of any chemical reaction is one where the...... decrease.

1. Entropy               

2. Enthalpy

3. Gibbs energy       

4. None of the above

Entropy decreases during:

1. crystallization of sucrose from solution

2. rusting of iron

3. melting of ice

4. vaporization of camphor

Entropy change of vaporization at constant pressure is given by:

1. $∆{\mathrm{S}}_{\mathit{(p}\mathit{)}}= \frac{∆{\mathrm{Hp}}_{}}{\mathrm{T}}$

2. $∆{\mathrm{S}}_{\mathit{\left(}v\mathit{\right)}}=\frac{∆{\mathrm{U}}_v}{\mathrm{T}}$

3. $∆{\mathrm{S}}_{\mathit{\left(}v\mathit{\right)}}= \frac{∆{\mathrm{H}}_v}{\mathrm{P}}$

4. None of the above

What is the entropy change for the reaction given below, 

2H₂ (g) + O₂ (g) $\to$2H₂O(l)

at temperature 300 K? Standard entropies of H₂ (g), O₂(g) and H₂O(l) are 126.6, 201.20 and 68.0 JK^-1mol^-1 respectively.

1. -318.4 JK^-1mol^-1                           .

2. 318.4 JK^-1mol^-1 

3. 31.84 JK^-1mol^-1                             

4. none of these

If S$°$ for H₂, Cl₂ and HCl are 0.13, 0.22 and 0.19 kJ K^-1mol^-1 respectively. The total change in standard entropy for the reaction, H₂ + Cl₂ $\to$2HCl is:

1. 30 J K^-1mol^-1                         

2. 40 J K^-1mol^-1

3. 60 J K^-1mol^-1                         

4. 20 J K^-1mol^-1

The standard change is Gibbs energy for the reaction,

H₂O$\rightleftarrows$H⁺ + OH^- at 25$°$C is:

1. 100 kJ                         

2. -90 kJ

3. 90 kJ                           

4. -100 kJ

The entropy change in the fusion of one mole of a solid melting at 27$°$C  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$°\mathrm{C}$ 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

For the process

H₂O(l) $\to$H₂O(g)

 at T=100$°$C and 1 atmosphere pressure, the correct choice is:

1. $∆{\mathrm{S}}_{\mathrm{system}}>0 \mathrm{and} ∆{\mathrm{S}}_{\mathrm{surrounding}}>0$

2. $∆{\mathrm{S}}_{\mathrm{system}}>0 \mathrm{and} ∆{\mathrm{S}}_{\mathrm{surrounding}}<0$

3. $∆{\mathrm{S}}_{\mathrm{system}}<0 \mathrm{and} ∆{\mathrm{S}}_{\mathrm{surrounding}}>0$

4. $∆{\mathrm{S}}_{\mathrm{system}}<0 \mathrm{and} ∆{\mathrm{S}}_{\mathrm{surrounding}}<0$