Thermodynamics & Solid State MCQs

For a van der Waals gas, the correction to pressure accounts for:

• Molecular size

• Intermolecular attractions

• Both (a) and (b)

• Only temperature

Which equation represents the change in Gibbs free energy for a process at constant temperature and pressure?

• dG = dU + PdV

• dG = dH - TdS

• dG = VdP - SdT

• dG = dU + TdS

For an ideal gas undergoing a reversible adiabatic expansion, the relationship between pressure and volume is:

• PV = nRT

• PV^γ = constant

• P/T = constant

• V/T = constant

In a multi-component system, the Gibbs phase rule is given by:

• F = C + P - 1

• F = C + 2 - P

• F = C - P + 2

• F = C × P - 2

The work done during the reversible isothermal compression of one mole of an ideal gas from volume V1 to V2 at temperature T is:

• nRT(V2 - V1)

• nRT ln(V2/V1)

• nRT ln(V1/V2)

• nR(V2 - V1)

For the reaction A ⇌ B at equilibrium at constant T and P:

• ΔG = 0

• ΔG < 0

• ΔG > 0

• ΔH = 0

Which is an exact differential?

• dQ

• dW

• dU

• dq

The area enclosed by a closed curve in a PV diagram represents:

• Change in internal energy

• Net heat supplied

• Net work done during the cycle

• Change in entropy

In a Joule-Thomson expansion, cooling occurs when:

• The inversion temperature is below the gas temperature

• The inversion temperature is above the gas temperature

• The process is adiabatic

• The process is isothermal

Which function reaches a minimum at equilibrium for a closed system at constant pressure and temperature?

• Internal energy

• Helmholtz free energy

• Enthalpy

• Gibbs free energy