Question

Which one of the following is correct for the isothermal expansion of an ideal gas?

• A. U and H increases
• B. U increases but H decreases
• C. U and H are unchanged
• D. H increases but U decreases

Answer 1

The correct option is C U and H are unchanged

In isothermal reversible process, ideal gas has constant temperature, $\Delta T=0$ and so $\Delta U=n{C}_v\Delta T=0$ and $\Delta H=n{C}_p\Delta T=0$.