During which the process of heat exchange with the external environment does not occur

During which the process of heat exchange with the external environment does not occur: isobaric isothermal mechanical adiabatic isochoric.

Adiabatic is a process in which heat is not absorbed or transferred to the outside. Accordingly, there is no heat exchange with the environment.

The first law of thermodynamics:

∆Q = ∆U + A

Since there is no change in heat, then the equation will take the form:

-∆U = A

That is, the gas can do work only by changing its internal energy. When positive work is done, the gas will expand and cool. When doing negative, shrink and heat up.