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          

The maximum work done in expanding 16 g of oxygen at 300 K and occupying a volume of 5 dm³ isothermally until the volume becomes 25 dm³ is:

1. -2.01 x 10³ J                       

2. 2.81 x 10³ J

3. 2.01 x 10^-3 J                     

4. -2.01 x 10^-6 J

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

 During an adiabatic process:

1. pressure is maintained constant

2. gas is isothermally expanded

3. there is perfect heat insulation

4. the system changes heat with surroundings

Heat of combustion $∆\mathrm{H}°$ for C(s), H₂(g) and CH₄(g) are -94, -68 and -213 kcal/mol. Then, $∆\mathrm{H}°$ for 

C(s) + 2H₂(g) $\to$CH₄(g) is                                                                 

1. -17 kcal/mol                         

2. -111 kcal/mol

3. -170 kcal/mol                       

4. -85 kcal/mol

What is the resulting change in the internal energy of the system when 50 calories are added to
the system and the system does work of 30 calories on the surroundings?

1. 20 cal                             
2. 50 cal
3. 40 cal                             
4. 30 cal

For the process:

H₂O(l)[1 bar, 373 K] $\rightleftharpoons$H₂O(g)[1 bar, 373 K] the correct set of thermodynamic parameters are:

1. $∆\mathrm{G}=0; ∆\mathrm{S}=+\mathrm{ve}$

2. $∆\mathrm{G}=0; ∆\mathrm{S}=-\mathrm{ve}$

3. $∆\mathrm{G}=+\mathrm{ve}; ∆\mathrm{S}=0$

4. $∆\mathrm{G}=-\mathrm{ve}; ∆\mathrm{S}=+\mathrm{ve}$

The internal energy change when a system goes from state A to B is 40 kJ/mol. If the system goes from A to B by a reversible path and returns to state A by an irreversible path. What would be the change in internal energy?

1. 40 kJ                                   

2. >40 kJ

3. <40 kJ                                 

4. Zero