The entropy of change involved in the isothermal reversible expansion of 2 moles of an ideal gas from a volume of `10 dm^(3)` to a volume of `100 dm^(3) at 27^(@)C` is

Options

A. `38.3 J mol^(-1) K^(-1)`
B. `35.8 J "mol"^(-1) K^(-1)`
C. `32.3 J "mol"^(-1) K^(-1)`
D. `42.3 J "mol"^(-1) K^(-1)`

Answer

A

Explanation

`DeltaS = 2.303 nR "log (V_(2))/(V_(1))`
` = 2.303 xx 2 xx 8.314 "log (100)/(10)`
` = 2.303 xx 2 xx 8.314 xx 1`
`= 38.3 J "mol"^(-1) K^(-1)`
`DeltaH = DeltaU + Deltan_(g)RT`
`DeltaU = DeltaH - Deltan_(g)RT`
`Deltan_(g) = 2 -3 = -1`
`DeltaU = -1366.5 - (-1) xx 8.314 xx 10^(-3) xx 300`
`= -1366.5 + 2.494`
=`- 1364.0`