C343 - Experiment #2 + #3 Extraction and Evaporation Separating Panacetin/Identifying Components

The chemicals involved

aspirin, acetaminophen, acetanilide, phenacetin

How can we separate components?

Boiling point, distillation, acid/base separation, etc.

1st step separating panacetin

adding dichloromethane and filtrating

solid product (after dichloromethane is added)

sucrose

filtrate after dichloromethane

aspirin + unknown

The filtrate

absorbs in dichloromethane

How can we organize separation?

flow chart

how can we separate aspirin and unknown

Extract with NaHCO3 (separatory funnel)

Aqueous layer

sodium acetylsalicylate in water

organic layer

unknown (in dichloromethane)

Sodium acetylsalicylate in water

add HCl, filtrate, identifies as aspirin

unknown

must evaporate it before identifying it

NaHCO3

helps separate the unknown and sodium acetylsalicylate without completely neutralizing it

What happens if acetaminophen was the unknown instead of acetanilide or phenacetin?

acetaminophen would get protonated and you wouldn’t be able to differentiate the layers

acetanilide

lower melting point with higher solubility and low molecular weight

phenacetin

higher melting point with lower solubility and higher molecular weight

What layer goes on top of the separatory funnel?

Lower density

What would not be soluble in water?

Long-chain alcohols, typically those with 8 or more carbon atoms/cyclo’s that fit those criteria as well

Which of the following outcomes would most possibly occur if you initially dissolved the panacetin mixture in a more polar organic solvent, still immiscible in water, instead of dichloromethane?

increased % of recovered sucrose (more impure, wouldn’t fully dissolve the other components)

What do you need to separate panacetin initially?

a good perfectly polar organic solvent

Two organic compounds have similar solubility in water but one is alcohol and another is carboxylic acid. Which of the following can help separate them from organic layer?

A strong base will dissolve in water

If an impurity exists in a sample, the melting point _________ and ________.

broadens and lowers

What is one way to identify a compound using instrumental analysis? 

NMR Spectroscopy