Class 11 NEET Chemistry Chemical Thermodynamics

An isothermal process is a change of a system, in which the temperature remains constant. For an ideal gas during an isothermal expansion the enthalpy, as well as internal energy, remains constant.
During isothermal expansion of an ideal gas, ∆E=0,∆T=0
From the definition of enthalpy, H=E+PV
or ∆H=∆E+∆(PV)
or ∆H=∆E+∆(nRT) \{ Since, PV=nRT for an ideal gas\}
or ∆H=∆E+nR∆T
or ∆H=0