Search any question & find its solution
Question:
Answered & Verified by Expert
An ideal gas expands by performing $200 \mathrm{~J}$ of work, during this internal energy increases by $432 \mathrm{~J}$. What is enthalpy change?
Options:
Solution:
1518 Upvotes
Verified Answer
The correct answer is:
$632 \mathrm{J}$
Assuming constant pressure,
$\Delta \mathrm{H}=\Delta \mathrm{U}+\mathrm{P}_{\mathrm{ext}} \Delta \mathrm{V}=\Delta \mathrm{U}-\mathrm{W}$
Work done $(\mathrm{W})=-200 \mathrm{~J}$ (for expansion of a gas)
$\begin{aligned}
& \Delta \mathrm{U}=+432 \mathrm{~J} \\
& \Delta \mathrm{H}=\Delta \mathrm{U}-\mathrm{W}=+432-(-200)=+632 \mathrm{~J}
\end{aligned}$
$\Delta \mathrm{H}=\Delta \mathrm{U}+\mathrm{P}_{\mathrm{ext}} \Delta \mathrm{V}=\Delta \mathrm{U}-\mathrm{W}$
Work done $(\mathrm{W})=-200 \mathrm{~J}$ (for expansion of a gas)
$\begin{aligned}
& \Delta \mathrm{U}=+432 \mathrm{~J} \\
& \Delta \mathrm{H}=\Delta \mathrm{U}-\mathrm{W}=+432-(-200)=+632 \mathrm{~J}
\end{aligned}$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.