Question

4. If 62.8 g Ca react with 92.3 g HCl according to the reaction below, how many grams of hydrogen gas will be produced, and how many grams of the excess reactant will be left over?

Unbalanced equation: Ca + HCl → CaCl2 + H2

Be sure to show all of your work.

Thank you very much to who ever help me with this (:

Answer 1

This looks like a limiting reagent problem to me mixed in with some Stoichiometry. Looking at the chemical equation we need to check and see if its balanced and we can tell that it is not so we must start there.

\[Ca + 2HCl \rightarrow CaCl_2 +H_2\]

Now that we have a balanced chemical equation we can figure out which of the reagents are the limiting reactant Using Stoichiometry.

\[62.8 g Ca (\frac{1 mole Ca}{24.305g Ca})(\frac{1 Mole H_2}{1 Mole Ca})(\frac{2.02 g H_2}{1 mole H_2})=5.22gH_2\]

\[92.3g HCl (\frac{1 mole HCl}{36.454g HCl})(\frac{1 mole H_2}{2mole HCl})(\frac{2.02g H_2}{1mole H_2}) =2.56g H_2\]

At this point in time we can determine that HCl would be the limiting reactant and you would be able to produce 2.56g of hydrogen gas.