If the product of a reaction are nacl and h2o what does the law of conservation of mass reveal about the reactants in the reaction

The reactants must contain the same number of individual atoms and the reactants will be HCl and NaOH.

Explanation:

Reactants and products together form a chemical equation.

A balanced chemical equation always follow law of conservation of mass.

This law states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form. This also means that total number of individual atoms on reactant side must be equal to the total number of individual atoms on the product side.  

We are given:

Products are NaCl and . This means that the reactants will also have same number of individual atoms.

The chemical reaction in which the given products obtained are:

The given reaction is considered as a neutralization reaction because an acid reacts with a base to produce salt and water molecule.

Hence, the reactants must contain the same number of individual atoms and the reactants will be HCl and NaOH.