A2 Unit 1

Question 1

How can aldehydes be distinguished from ketones?
(3 ways)

Answer 1

1. Aldehydes change acidified potassium dichromate (VI) solution from orange to green
2. Aldehydes form a red precipitate when heated with Fehling’s solution
3. Aldehydes form a silver mirror when heated with Tollen’s reagent.

Question 2

What is observed when carboxylic acids react with sodium carbonate?

Answer 2

Solid disappears
Fizzing

Question 3

What is observed when carboxylic acids react with sodium hydroxide solution?

Answer 3

The mixture warms up

Question 4

What is observed when carboxylic acids react with aqueous ammonia?

Answer 4

Smell disappears

Question 5

What is observed when carboxylic acids react with alcohols?

Answer 5

Sweet smell
detected with PCl5 - solid disappears, misty fumes, mixture warms up

Question 6

What is observed when acyl chlorides react with water?

Answer 6

Misty fumes
Mixture warms up

Question 7

What is observed when acyl chlorides react with alcohols?

Answer 7

Same reaction as with water, but less vigourous

Question 8

What is the product produced when methyl-3-nitrobenzoate is produced?

Answer 8

Cream solid