Preparation and Purification of Acetanilide

Question 1

Objective

Answer 1

• pick appropriate solvent for recrystallization
• separate and purify acetanilide from the mixture
• compare impure & recrystallization acetanilide with melting points

Question 2

What is active charcoal used for?

Answer 2

(decolorizer) gets rid of color impurities

Question 3

Solvent / Solvent pair criteria

Answer 3

sample needs to be sparingly soluble at room temperature but quite soluble at the boiling point of the solvent selected.

Question 4

Criteria for selecting a recrystalizing solvent

Answer 4

1. compound being purified must be insoluble in solvent at room temp
2. compound must be soluble in boiling solvent
3. solvent’s boiling point must be lower than the compounds melting point
4. an abundant quantity of crystals must be recoverable from the cool solvent

Question 5

A successful crystallization depends on a large difference between what two things?

Answer 5

• the solubility of a material in a hot solvent

- solubility in the same solvent when its cold

Question 6

What are the two key terms to know about crystallization?

Answer 6

1. It is wasteful

2. A crystallization is successful only if there is a small amount of impurity

Question 7

How is purification affected when the impurities are equally soluble in both the hot and cold solvent?

Answer 7

an effective impurification is not easily achieved through crystallization

Question 8

Oiling out refers to what occurrence during crystallization?

Answer 8

boiling point is higher than the compounds melting point sample which causes oil to form instead crystals

Question 9

Why is acetanilide known as an acylated aromatic amine?

Answer 9

because it has a acyl group substituted on its nitrogen

Question 10

Acetanilide, phenacetin, & acetaminohen are mild ____ and ____

Answer 10

analgesics (relieve pain) antipyretics (reduce fever)