Q9 / 160 · AP EAMCET 2024 (21 May Shift 2) · Chemistry
Identify the correct equation relating $\Delta H, \Delta U$ and $\Delta T$ for 1 mole of an ideal gas from the following ( $\mathrm{R}=$ gas constant)
- A$(\Delta H)^2=\Delta U+R \Delta T$
- B$\Delta \mathrm{H}=(\Delta \mathrm{U})^2+\mathrm{R} \Delta \mathrm{T}$
- Correct answerC$\Delta \mathrm{U}=\Delta \mathrm{H}-\mathrm{R} \Delta \mathrm{T}$
- D$\Delta \mathrm{U}=\Delta \mathrm{H}+\mathrm{R} \Delta \mathrm{T}$
Solution
Relation between $\Delta \mathrm{H}$ and $\Delta \mathrm{U}$ is
$\Delta \mathrm{H}=\Delta \mathrm{U}+\Delta \mathrm{n}_{\mathrm{g}} \mathrm{RT}$
or, $\Delta \mathrm{U}=\Delta \mathrm{H}-\Delta \mathrm{n}_{\mathrm{g}} \mathrm{RT}$
for 1 mole,
$\Delta \mathrm{U}=\Delta \mathrm{H}-\mathrm{RT}$
Hence, the correct answer is option: 'C'.