Q. At $27℃$, one mole of an ideal gas is compressed isothermally and reversibly from a pressure of 2 atm to 10 atm. The values of $\mathrm{\Delta}E$ and $q$ are $(R = 2)$
A) $0,\ - 965.84\ cal$
B) $- 965.84\ cal,\ - 865.58\ cal$
C) $+ 865.58\ cal,\ - 865.58\ cal$
D) $- 865.58\ cal,\ - 865.58\ cal$
Explanation
(a)
$W = 2.303\ nRT\log\frac{p_{2}}{p_{1}}$
$= 2.303 \times 1 \times 2 \times 300\log{\frac{10}{2} = 965.84}$
At constant temperature, $\mathrm{\Delta}E = 0$
$\mathrm{\Delta}E = q + W$;
$q = - W = - 965.84\ cal$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.