Thermodynamics

For isothermal expansion of an ideal gas, the correct combination of the thermodynamic parameters will be

• $∆$U = 0; Q = 0; W ≠ 0 and $∆$H ≠  0

• $∆$U ≠ 0; Q ≠ 0; W ≠ 0 and $∆$H =  0

• $∆$U = 0; Q ≠ 0; W = 0 and $∆$H ≠  0

• $∆$U = 0; Q ≠ 0; W ≠ 0 and $∆$H =  0

The condition of spontaneity of a process is

• lowering of entropy at constant temperature and pressure

• lowering of Gibbs free energy of system at constant temperature and pressure

• increase of entropy of system at constant temperature and pressure

• increase of Gibbs free energy of the universe at constant temperature and pressure

Which of the following is correct?

• Evaporation of water causes an increase in disorder of the system

• Melting of ice causes a decrease in randomness of the system

• Condensation of steam causes an increase in disorder of the system

• There is practically no change in the randomness of the system when water is evaporated

Given, $∆$G°=-nFE°_cell and $∆$G° = -RT ln k. The value of n = 2 will be given by the slope of which line in the figure

• OA

• OB

• OC

• OD

For the given reaction,

H₂ (g) + Cl₂ (g) → 2H⁺ (aq) + 2Cl^- (aq); $∆\mathrm{G}°$ = -262.4 kJ

The value of free energy of formation ($∆\mathrm{G}{°}_{\mathrm{f}}$) for the ion Cl^-1 (aq), therefore will be

• -131.2 kJ mol^-1

• +131.2 kJ mol^-1

• -262.4 kJ mol^-1

• +262.4 kJ mol^-1

Find the correct equation

• E₂ - E₁ - H₂ + H₁ = n₂RT - n₁RT

• E₂ - E₁ - H₂ - H₁ = n₂RT - n₁RT

• H₂ - H₁ - E₂ + E₁ = n₂RT - n₁RT

• H₂ - H₁ - E₂ - E₁ = n₂RT - n₁RT

The standard enthalpy of formation of H₂O (l) and Fe₂O₃ (s) are respectively -286 kJ mol^-1 and -824 kJ mol^-1. What is the standard enthalpy change for the following reaction?

Fe₂O₃ (s) + 3H₂ (g) → 3H₂O (l) + 2Fe (s)

• -538 kJ mol^-1

• +538 kJ mol^-1

• -34 kJ mol^-1

• +34 kJ mol^-1

Calculate $∆$H in kJ for the following reaction:

C (g) + O₂ (g) → CO₂ (g)

Given that, 

H₂O (g) + C (g) → CO (g) + H₂ (g) ; $∆$H = +131 kJ

CO (g) + $\frac{1}{2}$O₂ (g) → CO₂ (g); $∆$H = -282 kJ

H₂ (g) + $\frac{1}{2}$O₂ (g) → H₂O (g); $∆$H = -242 kJ

• -393

• +393

• +655

• -655

To convert 94 g of ice at 0°C into 94g of vapour at 100° C, the quantity of coal (90% carbon) required is : (ΔH_c of carbon = -94 k cal mol^-1);latent heat of fusion = + 80 cal per gm; latent heat ofvaporisation=+ 540 cal per gm; specificheat of water = 1 cal per gm per °C).

• 94g

• 80g

• 9.4g

• 9.6 g

Match List I with List II and select the correct answer using the codes.

• A   B   C   D

  4   2   1    3

• A   B   C   D

  3   1    2   4

• A   B   C   D

  1   3    4   2

• A   B   C   D

  1   2    3   4