When fat comes in contact with sodium hydroxide, it produces soap and glycerin. determine whether this is a physical change or a chemical change. explain your answer

chemical change

Explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.  Example: Evaporation of water

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions. Example: Combustion

As in the given reaction, fat comes in contact with sodium hydroxide to produce soap and glycerin, it will be a chemical change as new substances are being formed.

triglyceride + sodium hydroxide glycerol +3 soap molecules