You can calculate the mass of a product derived from a given mass of a reactant using stoichiometry and the balanced chemical equation of the reaction.

Stoichiometry is a branch of chemistry that focuses on the quantitative relationships among the reactants and products involved in chemical reactions. To ascertain the mass of a product from a known mass of a reactant, it’s essential to grasp the concept of a mole and to have the balanced chemical equation for the reaction at hand.

First, convert the given mass of the reactant into moles. This conversion is accomplished by dividing the mass of the reactant by its molar mass, which can be found in the periodic table. The molar mass represents the mass of one mole of a substance and is typically expressed in grams per mole (g/mol).

Next, refer to the balanced chemical equation for the reaction. This equation provides the ratio of moles of reactants to moles of products. For instance, in the reaction

two moles of hydrogen react with one mole of oxygen to yield two moles of water. This indicates that for every two moles of hydrogen consumed, two moles of water are produced.

Once you have determined the number of moles of the reactant, you can utilize the balanced equation to calculate the number of moles of the product formed. In the previous example, if you started with one mole of hydrogen, you would produce one mole of water, as the ratio of hydrogen to water is $2:2$, which simplifies to $1:1$.

Finally, convert the number of moles of the product back into mass by multiplying by the molar mass of the product. This calculation will yield the mass of the product that can be generated from the specified mass of the reactant.

Keep in mind that this method assumes the reaction goes to completion without any side reactions or losses. In practice, many reactions do not proceed to completion, and there may be side reactions or losses, meaning the actual mass of the product obtained may be less than the theoretical mass predicted by stoichiometry.