Question:

An ideal gas undergoes isothermal compression from 5 \(\mathrm{m^3}\) to 1 \(\mathrm{m^3}\) against a constant external pressure of 4 \(\mathrm{N\,m^{-2}}\). Heat released in this process is used to increase the temperature of 1 mole of Al. If molar heat capacity of Al is 24 \(\mathrm{J\,mol^{-1}\,K^{-1}}\), the temperature of Al increases by :

Show Hint

For an isothermal process on an ideal gas, \(\Delta U = 0\) so heat released equals the work done on the gas, \(P_{ext}\,|\Delta V|\).
Updated On: Nov 5, 2026
  • \(\frac{2}{3}\,\mathrm{K}\)
  • \(\frac{3}{2}\,\mathrm{K}\)
  • 1 K
  • 2 K
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Work done on the gas: \(w = -P_{ext}\,\Delta V = -4 \times (1 - 5) = +16\ \mathrm{J}\).
Isothermal, ideal gas: \(\Delta U = 0\), so \(q = -w = -16\ \mathrm{J}\). The gas releases 16 J.
This heat raises the temperature of 1 mol Al: \(q = nC\Delta T\), so \(\Delta T = \frac{16}{1 \times 24} = \frac{2}{3}\ \mathrm{K}\).
Answer: (1) \(\frac{2}{3}\,\mathrm{K}\)
Was this answer helpful?
0
0