Q. Two moles of an ideal gas undergo free expansion from 10 L to 100 L at 300 K. The values of ΔS(system) and ΔS(surroundings) are (R is universal gas constant)
A) ΔS(system) = 4.606R; ΔS(surroundings) = 0
B) ΔS(system) = 0; ΔS(surroundings) = 0
C) ΔS(system) = 4.606R; ΔS(surroundings) = −4.606R
D) ΔS(system) = 0; ΔS(surroundings) = 4.606R
Explanation
[Solution from source] Entropy is a state function, so ΔS(system) = nR ln(V₂/V₁) = 2R ln 10 = 4.606R. In free expansion no heat is exchanged with the surroundings, so ΔS(surroundings) = 0. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.