Chemical Thermodynamics MCQs with Explanations

5.76 is the correct answer to “Standard entropy of crystalline carbon monoxide (in kJ/mol) at 0 K is around”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

greater than zero is the correct answer to “For an irreversible adiabatic expansion of a perfect gas from volume V i to V f , the change in entropy of the gas is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

12.74 J/K/mol is the correct answer to “The change in entropy when two moles of argon gas are heated at constant volume from 300 K to 500 K is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

ΔS° = -198.7 J/K/mol; negative sign indicates that there is a decrease in the gaseous species during the reaction is the correct answer to “For the reaction, N 2 (g) + 3H 2 (g) → 2NH 3 (g) compute the entropy change (in J/K/mol) for the process and comment on the sign of the property. Data Species S°(J/K/mol) NH 3 (g) 192.3 N 2 (g) 191.5 H 2 (g) 130.6”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

-114.2 kJ is the correct answer to “Given that standard molar enthalpies of formation of NO(g) and NO 2 (g) are respectively 90.3 kJ/mol and 33.2 kJ/mol, the enthalpy change for the reaction 2NO(g) + O 2 (g) → 2NO 2 (g) is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

ΔG = 78.2 kJ/mol and the reaction is not feasible is the correct answer to “The standard free energies of formation of H 2 S(g) and CdS(s) at 1000°C are -49.0 kJ/mol and -127.2 kJ/mol respectively. Use these data to predict whether H 2 (g) will reduce CdS(s) to metallic Cd at this temperature.”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

ΔG, ΔH and ΔS are negative is the correct answer to “For the reaction, 2Cl(g) → Cl 2 (g) the thermodynamic properties”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

negative is the correct answer to “According to conventional transition state theory, for elementary bimolecular reactions, the molar entropy of activation ΔS ± is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

Ag(s) + $$\frac{1}{2}$$Cl2(g) → AgCl(s) is the correct answer to “The enthalpy of formation of AgCl is obtained from the enthalpy change from which one of the following process”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

-27.57 J/K/mol is the correct answer to “For the process, 1Ar(300 K, 1 bar) → 1Ar(200 K, 10 bar) assuming ideal gas behaviour, the change in molar entropy is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

the enthalpy of vaporization is always endothermic is the correct answer to “The rate of evaporation of a liquid is always faster at a higher temperature because”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

(dS)U,V > 0 is the correct answer to “Choose the correct criterion of spontaneity in terms of the properties of the system alone.”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

ΔSsys + ΔSsurr > 0 is the correct answer to “The criterion for the spontaneity of a process is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

R In2 is the correct answer to “The molar entropy of crystalline CO at absolute zero is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

V is the correct answer to “$${\left( {\frac{{\partial G}}{{\partial p}}} \right)_T} = $$”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

150 g of water at 50°C is the correct answer to “Among the following, the system that would require the least amount of thermal energy to bring its temperature to 80°C is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

N2(g) + 3H2(g) → 2NH3(g) is the correct answer to “Among the following, the reaction that is accompanied by a decrease in the entropy is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

dGp,V ≤ 0 is the correct answer to “The criterion for spontaneous change in terms of the state functions is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

RT In2 is the correct answer to “The free energy change (ΔG) of 1 mole of an ideal gas that is compressed isothermally from 1 atm to 2 atm is”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

W and Q are path functions but U and S are state functions is the correct answer to “Among W (work), Q (heat), U (internal energy) and S (entropy)”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.

ΔH = ΔE - 3RT is the correct answer to “ΔH and ΔE for the reaction, Fe 2 O 3 (s) + 3H 2 (g) → 2Fe(s) + H 2 O($$l$$) at constant temperature are related as”. This question is standard in competitive examination syllabi for Chemical Thermodynamics.