One mole of an ideal gas is expanded irreversibly from an initial pressure of 2 atm to a final pressure of 1 atm at a temperature of 300 K . Let $q_{\mathrm{irr}}, \Delta S_{\text {sys }}$ and $\Delta S_{\text {surr }}$ represent the magnitude of the heat transfer, the entropy change of the system, and the entropy change of the surrounding respectively. Assuming that the surrounding does not perform any work, the correct relation(s) is/are ( $R$ is the universal gas constant)

• Correct answer
  A

  $\Delta S_{\text {surr }}=-q_{\text {irr }} / 300$
• Correct answer
  B

  $\Delta S_{\mathrm{sys}}=R \ln 2$
• C

  $\Delta S_{\mathrm{sys}}=q_{\mathrm{irr}} / 300$
• Correct answer
  D

  $q_{\text {irr }} \lt 300 R \ln 2$

Hence, the correct answer is options: 'A', 'B', 'D'.