Given the following, how many g of calcium chloride will be produced when 28.0 g of calcium carbonate are combined with 12.0 g of hydrochloric acid? Which reactant is in excess and how many g of this reactant will remain after the reaction is complete?

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

1 Answer
Nov 19, 2016

"CaCO"_3"CaCO3 is the reactant in excess.
The amount of "CaCO"_3"CaCO3 remaining is "11.5 g"11.5 g.

Explanation:

Write a balanced equation.

"CaCO"_3 + "2HCl"CaCO3+2HClrarr"CaCl"_2 + "CO"_2 + "H"_2"O"CaCl2+CO2+H2O

Use the balanced equation to determine the mole ratios between "CaCO"_3"CaCO3 and "CaCl"_2"CaCl2 and between "HCl"HCl and "CaCl"_2"CaCl2 and between "CaCO"_3"CaCO3 and "HCl"HCl

Calcium carbonate and calcium chloride.

"1 mol CaCO"_3/"1 mol CaCl"_2"1 mol CaCO31 mol CaCl2 and "1 CaCl"_2/"1 mol CaCO"_3"1 CaCl21 mol CaCO3

Hydrochloric acid and calcium chloride.

"2 mol HCl"/"1 CaCl"_2"2 mol HCl1 CaCl2 and "1 mol CaCl"_2/"2 HCl"1 mol CaCl22 HCl

Calcium carbonate and hydrochloric acid.

"1 mol CaCO"_3/"2 mol HCl"1 mol CaCO32 mol HCl and "2 mol HCl"/"1 mol CaCO"_3"2 mol HCl1 mol CaCO3

Determine the moles of each reactant by dividing the given masses by their molar masses.

28.0 cancel"g CaCO"_3xx(1 "mol CaCO"_3)/(100.1 cancel"g CaCO"_3)="0.280 mol CaCO"_3"

12.0cancel"g HCl"xx(1"mol HCl")/(36.5cancel"g HCl")="0.329 mol HCl"

Determine the mass of "CaCl"_2" produced by each reactant by multiplying the moles of each reactant times the mole ratios with "CaCl"_2" in the numerator. Then multiply the result by the molar mass of "CaCl"_2" ("111 g/mol").

Calcium carbonate

0.280 cancel"mol CaCO"_3xx(1cancel"mol CaCl"_2)/(1cancel"mol CaCO"_3)xx(111"g CaCl"_2)/(1cancel"mol CaCl"_2)="31.1 g CaCl"_2"

Hydrochloric acid

0.329cancel"mol HCl"xx(1cancel"mol CaCl"_2)/(2cancel"mol HCl")xx(111"g CaCl"_2)/(1cancel"mol CaCl"_2)="18.3 g CaCl"_2"

Since hydrochloric acid yields less calcium chloride than calcium carbonate, it is the limiting reactant .

Calcium carbonate is the excess reactant .

Determine the mass of "CaCO"_3" that reacted with the limiting reactant "HCl".

0.329 cancel"mol HCl"xx(1cancel"mol CaCO"_3)/(2cancel"mol HCl")xx(100.1"g CaCO"_3)/(1cancel"mol CaCO"_3)="16.5 g CaCO"_3color(white)(.)"reacted"

To determine the mass of "CaCO"_3" that remains, subtract the mass that reacted from the starting mass.

"28.0 g"-"16.5 g"="11.5 g"