Question

The difference between $\Delta H$ and $\Delta U$ is usually significant for systems consisting of

• A. only solids
• B. only liquids
• C. both solids and liquids
• D. only gases

Answer 1

Answer: (D)

The difference between $\Delta H$ and $\Delta U$ is not usually significant for systems consisting of only solids or liquids. Solids and liquids do not suffer any significant volume changes upon heating. The difference, however, becomes significant when gases are involved.