Which statement is true about a reversible reaction?

it has equal mass of all reactants.
it produces salts from acids and bases.
it has equal number of products and reactants.
it results in an equilibrium mixture of reactants and products.

The correct statement is : It results in an equilibrium mixture of reactants and products.

Explanation:

A reversible chemical reaction is one that occurs in both directions, that is, of the reagents to generate products and vice versa. In synthesis, they are incomplete reactions since the reagents are not consumed in their entirety, since the products react to generate them again.

Explanation:

64.0g O2 1mol O2 2mol H2O 18.02g H2O

32.00 g O2 1mol O2 1mol H2O

= 72.08 g H2O = 72.1 g H2O