Posted by Yaw on Tuesday, November 27, 2012 at 1:34am.
I asked this already but for some reason the answer I got isnt being accepted online
In the laboratory, 3.50 grams of salicylic acid were reacted with 7.20 ml of acetic anhydride (density equal to 1.08 g/ml). Determine the limiting reagent.
salicylic acid + acetic anhydride → acetyl salicylic acid + acetic acid
C6H4(OH)COOH + (CH3CO)2O → CH3COOC6H4COOH + CH3COOH
moles C6H4(OH)COOH = (mass C6H4(OH)COOH) / (mole mass C6H4(OH)COOH)
moles C6H4(OH)COOH = (3.50 g) / (138.12354 g/mol)
moles C6H4(OH)COOH = 0.025396 mol
density (CH3CO)2O = [mass (CH3CO)2O] / [volume (CH3CO)2O]
mass (CH3CO)2O = [density (CH3CO)2O][volume (CH3CO)2O]
mass (CH3CO)2O = [1.08 g/mL][7.20 mL]
mass (CH3CO)2O = 7.776 g
moles (CH3CO)2O = [mass (CH3CO)2O] / [mole mass (CH3CO)2O]
moles (CH3CO)2O = [7.776 g] / [102.09024 g/mL]
moles (CH3CO)2O = 0.0761679 mol
So the answer would be salycic acid b/c its the lower number 0.025 mol
BUT my answer is incorrect apparently. Is here something I did wrong?
CHEM HELP - DrBob222, Tuesday, November 27, 2012 at 11:37pm
Thanks for showing your work.
Nope. You're right on target and your numbers are correct. Salicylic acid is the limiting reagent. One of several things may be the problem.
1. You posted the wrong numbers.
2. You didn't post all of the problem.
3. The reaction you have is wrong.
4. The problem was given to you with the wrong numbers.
5. The database (key) is wrong.
But I can assure you that if the numbers you posted are correct and the equation is correct, then the limiting reagent is salicylic acid. In MOST of the aspirin problems the acetic anhydride is the limiting reagent but that isn't true here.
Answer This Question
More Related Questions
- Chemistry of Life Science - 1. In the introduction to this experiment, it states...
- CHEMISTRY-Explanation Please - In the laboratory, 3.50 grams of salicylic acid ...
- Chemistry - Two people were given 1.75 g salicylic acid and 2.00 mL of acetic ...
- chem - A chemist is commissioned to produce twenty pallets of aspirin: C7H6O3 (...
- Chemisty - How to calculate the theoretical yield of aspirin to be obtained when...
- chem - Aspirin, C9H8O4, is produced from salicylic acid, C7H6O3, and acetic ...
- Chemistry - Aspirin is prepared by heating salicylic acid, C7H6O3, with acetic ...
- chemistry - For the theoretical yield, I used the mass of acetic anhydride. Was ...
- Chemistry - Aspirin can be prepared in the chemistry laboratory by the reaction ...
- chemistry - synthesis of aspirin - wanted to calculate the theoretical and ...