Why fuel and air has to be burned in an IC Engine?

Answer 1

The fuel wont burn without a catalyst. No oxygen...no burn!

Answer 2

The cylinders within an IC engine take in a mixture of fuel and air and compress it into a much smaller space. In doing so, the temperature rises (per the perfect gas equation) and the oxygen in the air is concentrated and act almost like pure oxygen. That supports rapid and complete combustion (burning not explosion) of the fuel releasing most of its available energy during the power stroke.

Answer 3

An IC Engine aims for harnessing impact energy from a controlled explosion of fuel and air in an enclosed space. Same process in open air will be useless coz all the energy will be wasted. Now its different in a rocket engine which uses Newton's Third Law to propel itself.
As soon as the fuel is combusted and explosive gases are released with high pressure, the piston is pushed down and the cycle continues and you get useful motion from the crankshaft.

Answer 4

YOu need oxygen to burn the fuel.. the mixtrure of the two in the correct ratio of about 14:1 (air; fuel) creates a combustible gas used to drive the pistons of the car.
Most materials rely on oxygen to be able to burn.. There are a couple of elements such as magnesium which doesn't need air.. it creates its own oxygen when burning.

Answer 5

I can't answer your question without getting it clear. IC- internal combustion? right? Pure fuel will not burn, on a cold day you can put a cigarette out in a can of gas because the gas isn't turning to vapor. The ideal ratio you're looking for is 14.7 parts air to 1 part fuel.

Answer 6

because it is more explosive than just liquid fuel.

it is the explosion that pushes the piston down, not the heat.

Answer 7

can't have combustion without oxygen