Exp 4: Principles of Chemically Active Extractions

Question 1

What is the structure of cellulose?

Question 2

What is the structure of benzoic acid?

Question 3

What is the structure of caffeine?

Question 4

What is the difference between an amide and amine?

Answer 4

Amide: Carbonyl with nitrogen attached
Amine: NH2 (or 1, 3) attached to carbon (number of carbons vs hydrogens determines primary, secondary, tertiary amine)

Question 5

Is the amine or amide basic?

Answer 5

amine (R-NH2: the lone pair on N can accept another hydrogen)

Question 6

What is the polarity of the amide group?

Answer 6

effectively neutral

Question 7

What did the addition of NaOH do in the experiment?

Answer 7

Converted benzoic acid to sodium benzoate

Question 8

What did the addition of HCl do in the experiment?

Answer 8

Reverted sodium benzoate to benzoic acid

Question 9

What was the reason for adding MgSO4?

Answer 9

To dry the organic layer

Question 10

How was MgSO4 removed from the organic layer?

Answer 10

gravity filtration

Question 11

How is percent recovery calculated?

Answer 11

= (mass recovered)/(actual mass) * 100%

Question 12

What was the reason for adding ice cold water to the aqueous layer?

Answer 12

to help precipitate benzoic acid still dissolved in the aqueous layer

Question 13

What is roto-vap short for?

Answer 13

rotary evaporatory