Question

In a reaction vessel, 17.6 g of solid chromium(III) oxide, Cr2O3, was allowed to react with excess carbon tetrachloride in the following reaction.
Cr2O3(s) + 3 CCl4(l) → 2 CrCl3(s) + 3 COCl2(aq)
Determine the percent yield of the reaction, given that the actual yield of chromium chloride, CrCl3, was 26.6 g. (The molar mass of Cr2O3 is 152.00 g/mol and the molar mass of CrCl3 is 158.35 g/mol.)

Answer 1

Answer:

72.53% is the yield of CrCl3

Explanation:

Given

Reaction:

Cr2O3(s) + 3 CCl4(l) → 2 CrCl3(s) + 3 COCl2(aq)

CCl4 is in excess and 17.6g  Cr2O3 present

The reaction yields 26.6g of CrCl3

To Find:

% yields of the reaction

Also given

Molar mass of CrCl3 = 158.35g/mol

Molar mass of Cr2O3 = 152.00 g/mol

By the stoichiometry of the reaction

1 mole of Cr2O3 gives  2 moles of CrCl3

0r

1 x1 52 g of Cr2O3 gives 2x 158.35 g of CrCl3

= 1 52 g of Cr2O3 gives 316.70 g of CrCl3

    17.6 g of Cr2O3 gives  (17.6÷152) × 316.70 g CrCl3

= 36.67 g CrCl3

but actual yield is only 26.6g

so % yield is (26.6 ÷÷ 36.67) × 100

= 72.53% is the yield of CrCl3