Which of the following statements is true concerning the decomposition of liquid water to form hydrogen gas and oxygen gas? 2H₂O(l)→ 2H₂(g)+ O₂(g) A)ΔH is greater than ΔU because the pressure is constant. B)ΔH is less than ΔU because of the pressure-volume work done by the gaseous products. C)ΔH is less than ΔU because the atmosphere does pressure-volume work on the gaseous products. D)ΔH equals ΔU because both are state functions. E)ΔH is greater than ΔU because of the pressure-volume work done by the gaseous products.

Question

Quizplus · Accepted Answer

The correct answer is E because during the decomposition of liquid water into hydrogen and oxygen gases, the system does work on the surroundings due to the expansion of gases. This work is pressure-volume work. According to the relationship ΔH = ΔU + PΔV, where ΔH is the change in enthalpy, ΔU is the change in internal energy, and PΔV represents the work done by the system at constant pressure, if the system does work on the surroundings (expansion), ΔH will be greater than ΔU because the PΔV term is positive.

Which of the Following Statements Is True Concerning the Decomposition