Chemistry - Thermodynamics - I Question with Solution | TestHub

In adiabatic process, no heat enters or leaves the system. The system is completely insulated from its surroundings. From first law of thermodynamics, change in internal energy, $$\Delta E=q-W=0-W=-W.$$ Since the work is done at the expense of internal energy, therefore internal energy of the system decreases and hence temperature of the gas falls.