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

The work done by a mass less piston in causing an expansion $∆$V (at constant temperature), when the opposing pressure, P is variable, is given by:

1. W= $-\int \mathrm{P}∆\mathrm{V}$               

2. W=0

3. W= -P$∆$V                     

4. none of these

Entropy decreases during:

1. crystallization of sucrose from solution

2. rusting of iron

3. melting of ice

4. vaporization of camphor

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

Change in entropy is negative for:

1. Bromine (l)$\to$Bromine(g)

2. C(s) + H₂O(g) $\to$CO(g) + H₂(g)

3. N₂(g,10 atm)$\to$N₂(g,1 atm) 

4. Fe ( 1mol, 400 K) $\to$ Fe( 1mol, 300 K)

Which statements are correct?

1. $2.303 \log \frac{{\mathrm{P}}_2}{{\mathrm{P}}_1}=\frac{∆{\mathrm{H}}_{\mathrm{vap}.}}{\mathrm{R}}\frac{\left[{\mathrm{T}}_2-{\mathrm{T}}_1\right]}{{\mathrm{T}}_1{\mathrm{T}}_2}$ is called Clausius-Clapeyron equation

2. $\frac{∆{\mathrm{H}}_{\mathrm{vap}.}}{\mathrm{Boiling} \mathrm{Point}}=88 J mo{l}^{-1}{K}^{-1}$ is called Trouton's rule

3. Entropy is a measure of unavailable energy, i.e.,

     unavailable energy = entropy x temperature

4. All of the above

A gaseous system changes from state A(P₁, V₁, T₁) to B(P₂,V₂,T₂), B to C(P₃, V₃, T₃) and finally from C to A. The whole process may be called:

1. reversible process                           

2. cyclic process

3. isobaric process                               

4. spontaneous process

All the naturally occurring processes, i.e., spontaneous proceed spontaneously in a direction that leads to:

1. decrease of free energy                     

2. increase of free energy

3. decrease of entropy                           

4. increase of enthalpy

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