JEE Main2013ChemistryThermodynamics (C)Actual
A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 3 7 . 0 ∘ C . As it does so, it absorbs 208 J of heat. The values of q and w for the process will be (R = 8.314 J/mol K) (ln7.5 = 2.01)
Options
- Aq = - 2 0 8 J , w = + 2 0 8 J
- Bq = + 2 0 8 J , w = + 2 0 8 J
- Cq = + 2 0 8 J , w = - 2 0 8 J
- Dq = - 2 0 8 J , w = - 2 0 8 J
Correct answer
C. q = + 2 0 8 J , w = - 2 0 8 J
Step-by-step solution
Since, temperature remains constant, the process will be isothermal by nature. For Isothermal reversible expansion: Δ E = 0 = q + w q = - w q = + 2 0 8  J    heat absorbed so +ve w = - 2 0 8  J expansion so work done is -ve