A2.9 Carbonyls

Question 1

Nitriles

Answer 1

Carbon triple bonded to nitrogen

Question 2

Hydroxynitriles

Answer 2

Carbon triple bonded to nitrogen and an OH group on the chain

Question 3

Test for carbonyls

Answer 3

2,4-DNP

Orange precipitate

Precipitate can be recrystallised and mp measured to identify specific compound

Question 4

Test for aldehydes

Answer 4

Tollens Reagant

Silver mirror

Question 5

Test for primary and secondary alcohols and aldehydes

Answer 5

Acidified potassium dichromate

Orange to green

Question 6

Test for carboxylic acid

Answer 6

Na2CO3

Effervescence

Question 7

Test for Alkenes

Answer 7

Bromine water

Decolourises

Question 8

Test for Phenol

Answer 8

pH < 7 using indicator paper or pH meter

Doesn’t react with carbonates

Question 9

Carboxylic acid and metal oxide

Answer 9

Carboxylate salt + water

Question 10

Carboxylic acid + metal

Answer 10

Carboxylate salt + H2 gas

Question 11

Carboxylic acid + alkali

Answer 11

Carboxylate salt + water

Question 12

Carboxylic acid + metal carbonate

Answer 12

Carboxylate salt + water + CO2 gas

Question 13

Esters

Answer 13

C double bonded to O and single bonded to O

Alkylalkanoate

Alkyl - only bonded to one O

Alkanoate - bonded to both O

Question 14

Acyl chloride

Answer 14

Add oyl chloride

Question 15

Primary Amide

Answer 15

NH2 and double bond to O on end of chain

Add amide

Question 16

Secondary and tertiary amide

Answer 16

N and double bond to O on same carbon
More chains off the N

N-ethylbutanamide

Question 17

Exception for tertiary alcohol

Answer 17

Carboxylic acid ——> ester