Chemical Thermodynamics Questions

15 Practice QuestionsStart Practicing Now

[Medium]A non-spontaneous reaction can proceed if coupled with a more exergonic one because total ΔG:...
[Easy]At constant T and P, spontaneity criterion is:...
[Easy]Third Law of Thermodynamics states entropy of a perfect crystal at 0 K is:...
[Hard]Estimate ΔH (kJ mol⁻¹) for CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) using average bond enthalpies. (Data approximate: C–H: 413, O=O: 498, C=O in CO2: 799, O...
[Medium]For reversible isothermal expansion of an ideal gas, work done is maximum because:...
[Medium]In a coffee-cup calorimeter, dissolution of 5.00 g KCl (ΔHsol = +17.2 kJ mol⁻¹) in 100.0 g water causes temperature drop. Molar mass KCl ≈ 74.5 g mol⁻...
[Medium]Which statement correctly expresses the Second Law of Thermodynamics?...
[Easy]Which statement best describes Hess's Law?...
[Medium]At 298 K, a reaction has ΔH = +25 kJ mol⁻¹ and ΔS = +120 J mol⁻¹ K⁻¹. Is the reaction spontaneous at 298 K?...
[Easy]ΔH°f of elements in their most stable form at 298 K is:...
[Easy]Which change is typically endothermic?...
[Easy]For the reaction: 2C(graphite) + O2(g) → 2CO(g), ΔH = -221 kJ. What is the enthalpy change (ΔH) per mole of CO formed?...
[Medium]A 50.0 g sample of water is heated from 25.0°C to 45.0°C. (Specific heat of water = 4.18 J g⁻¹ K⁻¹). Heat absorbed (q) is:...
[Hard]For a reaction at 298 K, ΔG° = -9.9 kJ mol⁻¹. The equilibrium constant K is approximately (R = 8.314 J mol⁻¹ K⁻¹):...
[Easy]Which process has ΔS > 0 at constant temperature?...