Question

When is a substance said to be reduced in a chemical reaction.

Answer 1

hloo frnd and your answer is as follows...

If a substance gains hydrogen or combines with hydrogen, it is said to be reduced.More precisely, the substance which gains electrons is reduced in the reaction.On gaining electrons, the oxidation state/ charge on the substance decreases.

hope it helps u..☺☺

Answer 2

when a compound with 1 or more oxygen atoms looses oxygen, then it is said to be red reduced.
For example: CuO+H2----->Cu+H20
Here copper is getting reduced