Question

Distinguish between as isothermal and an adiabatic process.

Answer 1

Hint: An isothermal process is a thermodynamic process that occurs under a constant temperature. Adiabatic process is a thermodynamic process that occurs without any heat transfer between a system and its surrounding.

Complete step by step answer:
Isothermal process
An isothermal process is a thermodynamic process in which the temperature of a system remains constant. The transfer of heat into or out of the system happens so slowly that thermal equilibrium is maintained. In other words, at a particular constant temperature, the change of a substance, object or system is known as Isothermal Process.
If a system is in contact with a thermal reservoir from outside, then, to maintain thermal equilibrium, the system slowly adjusts itself with the temperature of the reservoir through a heat exchanger. An isothermal process occurs in systems that have some means of regulating the temperature. This process occurs in systems ranging from complex machines to living cells.
Examples:
(i) Changes of phase of ice to water by melting
(ii) A refrigerator
(iii) Some Cycles of Carnot engine

Adiabatic process
An adiabatic process occurs without transferring heat or mass between a thermodynamic system and its surroundings. Unlike an isothermal process, an adiabatic process transfers energy to the surroundings only as work. No heat transfer occurs between a system and its surrounding. In this process, the temperature of the system is changed in order to keep the heat constant. This process is known as Adiabatic Process.
Difference

Sr. No.	Isothermal Process	Adiabatic process
(i)	The isothermal process occurs under constant temperature	The adiabatic process occurs under varying temperature
(ii)	The work done in an isothermal process is due to the change of net heat content of the system	The work done in an adiabatic process is due to the change in its internal energy.

Note:
An ideal gas is a hypothetical gas whose molecules don’t interact and face an elastic collision with each other. The Joule’s second law states that the internal energy of a fixed amount of an ideal gas only depends on the temperature. Thus, the internal energy of an ideal gas in an isothermal process is constant. In an isothermal condition, for an ideal gas, the product of Pressure and Volume (PV) is constant. This is known as Boyle’s law.