Saved Bookmarks
| 1. |
If \( 10 mol \) of an ideal gas expands reversibly and isothermally from \( 10 L \) to \( 100 L \) at \( 300 K \), then entropy change will be(1) -191.47 \( J K ^{-1} mol ^{-1} \)(2) \( 191.24 JK ^{-1} \)(3) \( 83.03 J K ^{-1} \) (4) \( 83.03 JK ^{-1} mol ^{-1} \) |
|
Answer» Correct option is (2) 191.24 J K-1 As we know \(\Delta S = nC_V\, ln\frac{T_2}{T_1} + nR\,ln\frac{V_2}{V_1}\) .....(1) ∵ Expansion occurs, reversibly and isothermally. ∴ The above equation (1) becomes- ∴ \(\Delta S = nR\, ln \frac{V_2}{V_1}\) .....(2) Putting the values of n, R, V2 and V1 in equation (2) - \(\Delta S = 10\times 8.314 \times ln \frac{100}{10}\) \(= 2.303 \times 10\times 8.314 \times log 10\) \(= 191.47 JK^{-1}mol^{-1}\) |
|