Question

A ${27}^{\circ }C$ one mole of an ideal gas is compressed isothermally and reversible from a pressure of $2atm$ to $10atm$. The value of $\Delta E$ and $q$ are $(R=2cal)$:

• A. $0,-965.84cal$
• B. $-965.84cal,-865.58cal$
• C. $+965.58cal,-865.58cal$
• D. $+965.84cal,+865.58cal$

Answer 1

The correct option is A $0,-965.84cal$

Isothermally (at constant temperature) and reversible work.
$w=2.303nRT\log \frac{P_2}{P_1}$
$=2.303\times 1\times 2\times 300\log \frac{10}{2}$
$=2.303\times 600\times \log 5$
$=965.84$
at constant temperature, $△E=0$
$△E=q+w,q=-w=-965.84cal$