Question

What does the total mass before a chemical reaction equal?

Answer 1

`"The total mass before a chemical reaction............"`

Explanation:

`"The total mass before a chemical reaction............"`

`"is EQUAL to the total mass after a chemical reaction."`

Mass is conserved in EVERY chemical reaction. This is why educators place such emphasis on `"stoichiometry"`, which requires that mass and atoms and molecules are balanced.

See here and here and links.