For silver, C_P( K^-1 mol^-1) = 23 + 0.01T. If the temperature (T) of 3 moles of silver is raised from 300 K to 1000 K at 1 atm pressure, the value of $∆$H will be close to :

• 21 kJ

• 62 kJ

• 16 kJ

• 13 kJ

Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas? (Assume non-expansion work is zero)

• Isothermal process : q = -w

• Cyclic process : q = -w

• Isochoric process : $∆\mathrm{U}$ = q

• Adiabatic process : $∆\mathrm{U}$ = -w

During compression of a spring the work done is 10 kJ and 2 kJ escaped to the surroundings as heat. The change in internal energy, $∆$U (in kJ) is:

• -12

• 8

• 12

• -8

Consider the given plot of enthalpy of the following reaction between A and B. A + B → C + D. Identify the incorrect statement.

• C is the thermodynamically stable product.

• Formation of A and B from C has highest enthalpy of activation.

• Activation enthalpy to form C is 5 kJ mol^-1 less than that to form D.

• D is kinetically stable product.

255.

5 moles of an ideal gas at 100 K are allowed to undergo reversible compression till its temperature becomes 200 K. If CV = 28 J K–1 mol–1, calcuIate ΔU and ΔPV for this process. ( R= 8.0 JK^-1 mol^-1 )

• ΔU = 14kJ; Δ(pV) = 18kJ

• ΔU = 14kJ; Δ(pV) = 0.8J

• ΔU = 14kJ; Δ(pV) = 4kJ

• ΔU = 2.8kJ; Δ(pV) = o.8J

Among the following, the set of parameters that represents path functions, is:

(A) q+w

(B) q

(C) w

(D) H-TS

• A, B and C

• B, C and D

• B and C

• A and D

A process will be spontaneous at all temperatures if :

• ΔH <0 and ΔS <0

• ΔH <0 and ΔS >0

• ΔH >0 and ΔS >0

• ΔH >0 and ΔS <0

The standard Gibbs energy for the given cell reaction in kJ mol^-1 at 298 K is:

Zn (s) + Cu²⁺ (aq) → Zn²⁺ (aq) + Cu (s), E° = 2V at 298 K

• -192

• 384

• -384

• 192

The difference between ΔH and ΔU ( ΔH- ΔU), when the combustion of one mole heptane(I) is carried out a temperature T, is equal to:

• -3RT

• -4RT

• 3RT

• 4R

The correct thermodynamic conditions for  the spontaneous reaction at all temperatures is

• ΔH> 0 and Δ S< 0
• ΔH< 0 and ΔS > 0
• ΔH ΔS >0
• ΔH ΔS >0