##### Chemistry solving problems

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Aspirin (C9H8O4) is produced from salicylic acid (C7H6O3), and acetic anhydride (C4H6O3), as shown below.

C7H6O3 + C4H6O3 → C9H8O4 + HC2H3O2

What is the theoretical yield of aspirin if 181 kg of salicylic acid is allowed to react with 124 kg of acetic anhydride?

If the situation described in part (c) produces 173 kg of aspirin, what is the percentage yield?

Jul 24th, 2015

SOLUTION:

Conversion of units:

1 kg = 1,000 g
1 mol C7H6O3 = 138.12354 g C7H6O3
1 mol C4H6O3 = 1 mol C7H6O3
1 mol C4H6O3 = 102.09024 g C4H6O3

[(181 Kg C7H6O3)/1][(1,000 g)/(1 Kg)][(1 mol C7H6O3)/(138.12354 g C7H6O3)][(1 mol C4H6O3)/(1 mol C7H6O3)][(102.09024 g C4H6O3)/(1 mol C4H6O3)][(1 Kg)/(1,000 g) = 134 Kg C4H6O3

Since only about 143 Kg of C4H6O3 is needed, as much as 167 Kg of C4H6O3 is available, we can assume that C4H6O3 is present in excess, and C7H6O3 is the determining reactant.

Conversion of units:

1 kg = 1,000 g
1 mol C7H6O3 = 138.12354 g C7H6O3
1 mol C9H8O4 = 1 mol C7H6O3
1 mol C9H8O4 = 180.16102 g C9H8O4

[(181 Kg C7H6O3)/1][(1,000 g)/(1 Kg)][(1 mol C7H6O3)/(138.12354 g C7H6O3)][(1 mol C9H8O4)/(1 mol C7H6O3)][(180.16102 g C9H8O4)/(1 mol C9H8O4)][(1 Kg)/(1,000 g) = 236 Kg C9H8O4

Answer: The theoretical yield is 252 Kg.

% yield = [(actual yield)(100%)] / (theoretical yield)
% yield of C9H8O4 = [(173 Kg)(100%)] / (236 Kg)
% yield of C9H8O4 = 73.3%

Answer: the percentage yield is 73.3%.

** P/S: Please remember to give me a review later on once the answer is correct. I would be highly appreciate it. Thank you. **
Jul 24th, 2015

** P/S: Please remember to give me a review later on once the answer is correct. I would be highly appreciate it. Thank you. **

Jul 24th, 2015

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Jul 24th, 2015
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Jul 24th, 2015
Dec 4th, 2016
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