Question

A sample of n moles of a monatomic ideal gas is expanded isothermally and reversibly at a constant temperature T from a volume V to 3V. Note that since the temperature of the gas is constant, the internal energy will remain constant.

a) Write an expression for the change in entropy ΔS for the system.

b) The sample has 7 moles of gas and is kept at a temperature of 305 K. The volume is changed from 0.065 m³ to (3)0.065 m³. What is the change in entropy, in joules per kelvin, if R = 8.314 J/(K mol)?

Answer 1

monoatomic gas degree of freedom f=3 a) In is othermal process V2 workctone W=MRT V₂ = 3V, =BV W= HRT en 1 3 v ♡ en :)

This work is done by the heat supplied to system oQ=W=nRT en (3) Entropy chonge os=oQ HRT IM (3) hren (3) T As = los=nR en (3) n=7moles ₂ = 0.065 m3, V2 = 3x0.065 m3 choinge in entropy Os=7Ren (3) Os=7x8.314 In (3) Os = 63.93Jk