Question

why should a fire caused by oil be put out by sand and not water

Answer 1

This is because the fire caused by oil creates a large amount of heat this water can split into Hydrogen and oxygen and increase the fire

Answer 2

If there is a fire caused by oil,we should always put it out by sand and not water as water always float above oil because of it's density or weight. So if fire occurs in oil and if we put water the fire will spread out and can cause harm.