Question

Why is water used as coolant?? please give reason and explain it briefly that why water is used as coolant in engines??

Answer 1

see hope it works if u can understand

Answer 2

An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert, and neither causes nor promotes corrosion of the cooling system.

……….

The most common coolant is water. Its high heat capacity and low cost makes it a suitable heat-transfer medium. It is usually used with additives, like corrosion inhibitorsand antifreeze. Antifreeze, a solution of a suitable organic chemical (most often ethylene glycol, diethylene glycol, or propylene glycol) in water, is used when the water-based coolant has to withstand temperatures below 0 °C, or when its boiling point has to be raised. Betaine is a similar coolant, with the exception that it is made from pure plant juice, and is therefore not toxic or difficult to dispose of ecologically.

I would also like to add that water had one of the lowest viscosities (Viscosity Tables), so it can dissipate the heat quicker. However, it does corrode metals (rust).

Another source (What property of water makes it useful as a coolant? | eNotes) states:

Actually, [water] has several [properties that make it useful as a coolant]. To be an effective coolant, a substance has to have a high specific heat capacity, meaning it can absorb a lot of heat. It also has to be nontoxic, or nonposionous. It also needs to be fairly common, which would mean since it is readily available, the cost should be fairly low. Water meets all these requirements. It is one of the most common compounds on Earth, covering nearly seventy-five percent of Earth's surface. It has a relatively high specific heat capacity, meaning it can transfer a lot of heat without breaking down itself. Water also has a low viscosity. Viscosity is a liquid's resistance to flowing; water flows quite easily. Water fits comfortably in at a 7 on the pH scale, meaning it is neither basic nor acidic in it's ability to act as either substance.