Internal combustion engines are always cooled by circulating a liquid known as engine coolant.
The coolant in an automobile radiator consists of a mixture of antifreeze and water.
The function of coolant is to absorb the excess heat from the engine parts and carry it via different passageways and tubes to the radiator where the excess heat is released into the atmosphere.
Water is not only used as a coolant since it boils at 100 Deg C and freezes at 0 Deg C.
Adding antifreeze increases the boiling point as well and reduces the freezing point.
Hence, the coolant is able to stay in liquid form at subzero temperatures.
As well as it can avoid boiling at high temperatures.
Coolant used:
Ethylene glycol is a chemical that is used in a variety of industrial and commercial applications.
Also in automobiles as an antifreeze and coolant.
Ethylene glycol has the ability to lower the freezing point of water, protecting the solution from freezing in cold environments.
Hence, the coolant used in car radiators is an aqueous solution of ethylene glycol.