hydrochloric acid

Question

When calcium carbonate is added to hydrochloric acid, calcium chloride, carbon dioxide, and water are produced.

CaCO3(s)+2HCl(aq)⟶CaCl2(aq)+H2O(l)+CO2(g)

A) How many grams of calcium chloride will be produced when 25.0 g of calcium carbonate is combined with 12.0 g of hydrochloric acid?

B) How many grams of the excess reactant will remain after the reaction is complete?

Answer 1

CaCO3(s) + 2HCl(aq) ==> CaCl2(aq) + H2O(l) + CO2(g) ... balanced equation

Find limiting reactant. Easy way is to divide mols of each reactant by its corresponding coefficient in the balanced equation.

For CaCO3: 25.0 g x 1 mol / 100 g = 0.25 mols CaCO3 (÷1->0.25)

For HCl: 12.0 g x 1 mol / 36.5 g = 0.329 mols HCl (÷2->-.016)

Since 0.16 is less than 0.25, HCl is the limiting reactant

a) grams of CaCl2 formed:

0.329 mols HCl x 1 mol CaCl2 / 2 mols HCl x 111 g CaCl2/ mol = 18.3 g CaCl2

b) grams CaCO3 remaining:

mols CaCO3 used = 0.329 mols HCl x 1 mol CaCO3 / 2 mol HCl = 0.165 mols CaCO3 used

mols remaining = 0.25 mols - 0.165 mols = 0.085 mols

grams remaining = 0.085 mols x 100 g / mol = 8.50 grams remaining