Question

The difference between $\Delta H$ and $\Delta U$ at constant volume is equal to

• A. $R$
• B. $P\Delta V$
• C. $V\Delta P$
• D. $\frac{3}{2}R$

Answer 1

Answer: (C)

$H=U+PV\Rightarrow \Delta H$

$=\Delta U+P\Delta V+V\Delta P$

At constant volume, $\Delta V=0$

Hence $\Delta H=\Delta U+V\Delta P$

i.e., $\Delta H-\Delta U=V\Delta P$