What happens to the plants if they are watered in hot water and the hot water is heated in the microwave will the plants die or grow faster?

Probably not because it is just hot water,and hot water cannot kill us.Here is a tip what ever water cannot hurt us cannot hurt plants. For example fresh water helps us so it helps them,or salt water it helps us in a way,but we cannot drink it so it does not help the plant or us.