Question

A sample containing 1.0 mole of an ideal gas is expanded reversibly and isothermally to ten times its original volume in two separate experiments. The expansion is carried out at 300 K and 600 K, respectively. Choose the correct option.

• A. (A) Work done at 600 K is twice the work done at 300 K.
• B. (B) Work done at 600 K is 20 times the work done at 300 K.
• C. (C) Work done at 300 K is twice the work done at 600 K.
• D. (D) ∆ U ≠ 0 in both cases.

Answer 1

Answer: (A)

(A) Work done at 600 K is twice the work done at 300 K.

Answer 2

Explanation:
For an ideal gas, the work of reversible expansion under isothermal conditions can be calculated by using the expansion w = -nRT ln Vf/Vi.W600KW300K=1×R×600×ln⁡1011×R×300×ln⁡101=2In isothermal expansion, ΔU=0