If one mole of an ideal gas (Cₚ,ₘ = 5/2R) is expanded isothermally at 300 K until it's volume is tripled change in entropy of gas is R in 3 if above expansion is carried out freely (Pₑₓₜ = 0) then find ΔS?
A. -R in 3
B. R in 2
C. R in 3
D. None of these