Question

Chlorine gas can be prepared in the laboratory by the reaction of hydrochloric acid with manganese(IV) oxide.

4HCl(aq)+MnO2(s)⟶MnCl2(aq)+2H2O(l)+Cl2(g)

A sample of 35.7 g MnO2 is added to a solution containing 43.1 g HCl.

what is the limiting reactant

What is the theoretical yield of Cl2?

If the yield of the reaction is 71.5%, what is the actual yield of chlorine?

Answer 1

4HCl(aq)+MnO2(s)⟶MnCl2(aq)+2H2O(l)+Cl2(g)

according to balanced reaction

4 x 36.46 g HCl reacts with 86.94 g MnO2

43.1 g HCl reacts with 43.1 x 86.94 / 4 x 36.46 = 3747.114 / 145.84 = 25.69 g MnO2

but we have 35.7 g MnO2. so MnO2 is exess reagent

Limiting reagent = HCl.

4 x 36.46 g HCl gives 71 g Cl2

43.1 g HCl gives 43.1 x 71 / 4 x 36.46 = 20.98 g

therotical yield of Cl2 = 20.98 g

% yield = (actual yield / therotical yield) x 100

71.5 = (actual yield / 20.98) x 100

actual yield / 20.98 = 0.715

actual yield of CL2 = 15.00 g