Which of the following is not a state function?

Work done in adiabatic process = negative of change in internal energy (from first law of thermodynamics). So it is a state function. For heat at constant pressure, dQ = nCpΔT. This is path independent. For work done in isothermal process, dQ = dW. This is path dependent and hence not a state function. Heat at constant volume is equal to change in internal energy (from first law of thermodynamics). So it is also a state function.