Obtain simplified expressions for β_T and α of an ideal gas.
Obtain simplified expressions for β_T and α of an ideal gas.
\beta _T=-\frac{1}{V} \left\lgroup\frac{∂V }{∂P} \right\rgroup _T , but V=\frac{RT}{P}:\left\lgroup\frac{∂V}{∂P} \right\rgroup_T =-\frac{RT}{P^2}:
\beta _T=\left\lgroup-\frac{1}{V} \right\rgroup .\left\lgroup-\frac{RT}{P^2} \right\rgroup =\frac{1}{P}
and \alpha =\frac{1}{V}\left\lgroup\frac{∂V}{∂T} \right\rgroup _P , but V=\frac{RT}{P}:\left\lgroup\frac{∂V}{∂T} \right\rgroup_P =\frac{R}{P} :
\alpha =\frac{1}{V}.\frac{R}{P} =\frac{1}{T}