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

Question

12.)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) How many grams of calcium chloride will be produced when 26.0 of calcium carbonate is combined with 15 g of hydrochloric acid?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

Step 1: Find which reactant, if any, is limiting...

mols CaCO₃ = 26.0 g x 1 mol / 100.0 g = 0.260 mols

mols HCl = 15 g HCl x 1 mol / 36.5 g = 0.411 mols

Limiting reactant = HCl (note it takes 2x the mols of HCl compared to mols CaCO₃ as per balanced equation)

Step 2: Calculate mass of CaCl₂ formed...

0.411 mols HCl x 1 mol CaCl₂ / 2 mols HCl x 111.0 g/mol = 22.8 g CaCl₂ formed (theoretical yield)

Step 3: Calculate mass excess reactant (CaCO₃) remaining...

mols CaCO₃ used up = 0.411 mols HCl x 1 mol CaCO₃ / 2 mols HCl = 0.2055 mols CaCO₃ used

mols CaCO₃ left over = 0.260 mols - 0.2055 mols = 0.0545 mols CaCO₃ remaining

mass CaCO₃ remaining = 0.0545 mols x 100. g/mol = 5.45 g = 5.5 g CaCO₃ remaining (2 sig. figs.)