JEE PYQ: Thermodynamics Question 21
Question 21 - 2019 (08 Apr Shift 2)
5 moles of an ideal gas at 100 K are allowed to undergo reversible compression till its temperature becomes 200 K. If $C_V = 28$ J K$^{-1}$ mol$^{-1}$, calculate $\Delta U$ and $\Delta(pV)$ for this process. ($R = 8.0$ J K$^{-1}$ mol$^{-1}$)
(1) $\Delta U = 14$ kJ; $\Delta(pV) = 18$ kJ
(2) $\Delta U = 14$ kJ; $\Delta(pV) = 0.8$ kJ
(3) $\Delta U = 14$ kJ; $\Delta(pV) = 4$ kJ
(4) $\Delta U = 14$ kJ; $\Delta(pV) = 8.0$ kJ
Show Answer
Answer: (3)
Solution
$\Delta U = nC_V\Delta T = 5 \times 28 \times 100 = 14$ kJ. $\Delta(PV) = nR(T_2 - T_1) = 5 \times 8 \times 100 = 4$ kJ.
BETA
