1.08 Percent Yield
The percent yield was calculated to be 171% indicating a source of error. The high percent yield was due to the product being wet since we did not have enough time to dry the product with the vacuum filter—since we had to evacuate the building due to the fire alarm. If we were able to vacuum filter our product more, the percent yield would be close to 100%.
1. Assign the peaks in your NMR spectrum of your salicylic acid.
See NMR spectrum on back
2. Assign the peaks in the IR spectrum of your salicylic acid.
The IR spectrum was not performed since we ran out of time due to the fire alarm.
3. What was the purpose of the hydrochloric acid?
Methyl salicylate reaction with NaOH gives sodium salt of carboxylic acid. The sodium salt of the acid and the phenol treated with HCl gives salicylic acid. In other words, HCl helps methyl salicylic precipitate since salicylic acid isn’t very soluble in an …show more content…
Report your percent yield and discuss how your percent yield could have been improved.
The percent yield was calculated to be 85% indicating a source of error. The low percent yield means that some product was lost. We most likely did not wash the flask enough since there was some amount of white substance on the sides of the flask. A lot of precipitate also did not form, so most of the product could have been filtered into the filtrate. We could have had a higher percent yield if we would have washed the sides of the flask more.
2. Assign the peaks in your NMR spectrum of your aspirin.
See graph on back.
3. Assign the peaks in the IR spectrum of your aspirin.
There was no IR spectrum for this lab.
4. What byproduct might have formed (think anhydride), and how might the addition of water helped convert this byproduct into the desired product?
Acetic acid might to be byproduct formed. In the presence of water, dehydration of acetic acid would not take place. Thus, the acetic acid obtained can further react with salicylic acid to give the desired
1. Assign the peaks in your NMR spectrum of your salicylic acid.
See NMR spectrum on back
2. Assign the peaks in the IR spectrum of your salicylic acid.
The IR spectrum was not performed since we ran out of time due to the fire alarm.
3. What was the purpose of the hydrochloric acid?
Methyl salicylate reaction with NaOH gives sodium salt of carboxylic acid. The sodium salt of the acid and the phenol treated with HCl gives salicylic acid. In other words, HCl helps methyl salicylic precipitate since salicylic acid isn’t very soluble in an …show more content…
Report your percent yield and discuss how your percent yield could have been improved.
The percent yield was calculated to be 85% indicating a source of error. The low percent yield means that some product was lost. We most likely did not wash the flask enough since there was some amount of white substance on the sides of the flask. A lot of precipitate also did not form, so most of the product could have been filtered into the filtrate. We could have had a higher percent yield if we would have washed the sides of the flask more.
2. Assign the peaks in your NMR spectrum of your aspirin.
See graph on back.
3. Assign the peaks in the IR spectrum of your aspirin.
There was no IR spectrum for this lab.
4. What byproduct might have formed (think anhydride), and how might the addition of water helped convert this byproduct into the desired product?
Acetic acid might to be byproduct formed. In the presence of water, dehydration of acetic acid would not take place. Thus, the acetic acid obtained can further react with salicylic acid to give the desired