An ideal gas ( (left.C_{P}=21.0 mathrm{~J} / mathrm{kmol} ight)) undergoes a constant-pressure change from (300 mathrm{~K}) to

An ideal gas ( \(\left.C_{P}=21.0 \mathrm{~J} / \mathrm{kmol}\right)\) undergoes a constant-pressure change from \(300 \mathrm{~K}\) to \(500 \mathrm{~K}\). The molar entropy of the gas at \(300 \mathrm{~K}\) is \(150 \mathrm{~J} / \mathrm{kmol}\). Find the entropy at \(500 \mathrm{~K}\).