This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: You have isolated caffeine from the over-the-counter pharmaceutical called NoDoz and wish to purify ... (Read 31 times)

ashley

  • Hero Member
  • *****
  • Posts: 584
on: Aug 23, 2018
You have isolated caffeine from the over-the-counter pharmaceutical called NoDoz and wish to purify it by recrystallization. Using the data in Table E9.1, explain which solvent you would use and why.

Question 2

Extra-strength Excedrin is a combination of 250 mg acetaminophen, 250 mg aspirin, and 65 mg caffeine plus inactive ingredients that are insoluble in water and organic solvents. Using the data in Table E9.1, draw a flowchart to show how these three components could be separated using their solubility and acid-base properties. Hint: Caffeine is a nitrogen base similar in reactivity to diisobutylamine.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

gasdhashg

  • Sr. Member
  • ****
  • Posts: 335
Reply #1 on: Aug 23, 2018
Answer to Question 1

The best solvent would be ethanol. The solubility of caffeine in water is extremely high at 100C, meaning that we would only need to start with 1.5 mL of water for every 1 gram of caffeine. The problem is that, when the solution is cooled to room temperature and then to ice-bath temperatures, almost all of the caffeine will crystallize out of a very small volume of solvent. This makes separating the solvent from the crystals difficult. This is not the case with ethanol, where a fair amount of solvent is required to get 1 gram of caffeine to dissolve at higher temperatures

Answer to Question 2



ashley

  • Member
  • Posts: 584
Reply 2 on: Aug 23, 2018
Excellent

JCABRERA33

  • Member
  • Posts: 344
Reply 3 on: Yesterday
Great answer, keep it coming :)

« previous next »
 

Did you know?

Fatal fungal infections may be able to resist newer antifungal drugs. Globally, fungal infections are often fatal due to the lack of access to multiple antifungals, which may be required to be utilized in combination. Single antifungals may not be enough to stop a fungal infection from causing the death of a patient.

Did you know?

Never take aspirin without food because it is likely to irritate your stomach. Never give aspirin to children under age 12. Overdoses of aspirin have the potential to cause deafness.

Did you know?

Though methadone is often used to treat dependency on other opioids, the drug itself can be abused. Crushing or snorting methadone can achieve the opiate "rush" desired by addicts. Improper use such as these can lead to a dangerous dependency on methadone. This drug now accounts for nearly one-third of opioid-related deaths.

Did you know?

Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.

Did you know?

In 1864, the first barbiturate (barbituric acid) was synthesized.

Mechanism of transport by a transporter, also called a carrier. Mechanism of transport by a transporter, also called a carrier.
Bay (left) and chestnut (sometimes called "sorrel") are two of the most common coat colors Bay (left) and chestnut (sometimes called "sorrel") are two of the most common coat colors
Persian leopard (Panthera pardus ciscaucasica), also called Caucasian leopard Persian leopard (Panthera pardus ciscaucasica), also called Caucasian leopard
Glioma. (a) Illustration of a large glioma (colored area) within the left cerebral hemisphere in a s Glioma. (a) Illustration of a large glioma (colored area) within the left cerebral hemisphere in a s
Cutaway Drawing of Tholos, The So-called Treasury of Atreus Cutaway Drawing of Tholos, The So-called Treasury of Atreus
Cystic fibrosis is caused by a mutation in a protein called CFTR Cystic fibrosis is caused by a mutation in a protein called CFTR
Video: Bond types - Atomic structure and basis of bonds

For a complete list of videos, visit our video library