Q. At 27$℃$ one mole of an ideal gas is compressed isothermally and reversible from a pressure of 2 atm to 10 atm. The value of $\mathrm{\Delta}E$ and q are (R=2 cal)
A) 0, -965.84 cal
B) -965.84 cal, -865.58 cal
C) +865.58 cal, -865.58 cal
D) +965.84 cal, +865.58 cal
Explanation
(a)
Isothermally (at constant temperature) and reversible work.
$W = 2.303\ nRT\log\frac{p_{2}}{p_{1}}$
$= 2.303 \times 1 \times 2 \times 300\log\frac{10}{2}$
$= 2.303 \times 600 \times \log{5 = 965.84}$
At constant temperature, $\mathrm{\Delta}E = 0$
$\mathrm{\Delta}E = q + W,\ q = - W = - 965.84$ cal
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.