In the complete reaction of 34.6 g of sodium with 21.8 g of chloride, what mass of sodium chloride is formed?

35.94 g of NaCl

Explanation:

First write a balanced chemical reaction.

2Na + Cl₂ --> 2NaCl

(Note that the Cl has a subscript of 2 because it's diatomic)

Then, set up an basic stoichiometry equation using one of the given masses of the reactants. I chose chloride.

The masses were acquired from the periodic table. (compound's mass requires the addition of individual element's masses) Also, the number of moles per reactant or product is based on the coefficient from the chemical reaction. I can't show this, but note that the units do cancel out so all that's left is grams of sodium chloride, which is what we were looking for.