During isothermal expansion of an ideal gas, its:

Options

A. inernal energy increases
B. enthalpy decreases
C. enthalpy remains unaffected
D. enthalpy reduces to zero.

Answer

C

Explanation

During isothermal expansion of ideal gas
`DeltaT=0`, Now `H=E+PV`
`:.DeltaH=DeltaE+Delta(PV)`
`:.DeltaH=DeltaE+Delta(nRT)`,
Thus if `DeltaT=0, DeltaH=DeltaE`
Thus if `DeltaT=0, DeltaH=DeltaE`
i.e. enthalpy remains unaffected