Question

μ moles of gas expands from volume V₁ to V₂ at constant temperature T. The work done by the gas is

(A) μRT {V₂ / V₁}               

(B) μRTln{V₂ / V₁}  

(C) μRT{(V_v / V₁) – 1}        

(D) μRTln {(V₂ / V₁)

Answer 1

Correct option: (B) μRT ln(V₂ / V₁)

Explanation:

Work done = ^(V)2∫_(V)1P ∙ dv……..(1)

Temperature is constant & no of moles = μ

Hence   PV = μRT

∴    P = [(μRT) / V]

∴ from (1), workdone = ^(V)2∫_(V)1 [(μRT) / V] ∙ dv

= μRT ln(V₂ / V₁)