What's in a Medicine?

Question 1

How is a ketone produced?

Answer 1

A secondary alcohol must be oxidised by acidified dichromate (VI). This must be heated under reflux.

Question 2

How is a carboxylic acid produced?

Answer 2

An aldehyde can be heated under reflux with acidified dichromate (VI). Or a primary alcohol can be heated under reflux.

Question 3

How do you distinguish between a ketone and an aldehyde?

Answer 3

Fehling’s solution can be added. This contains Cu2+ ions. An aldehyde can be oxidised so this causes the copper ions to be reduced to Cu+ ions. CuO precipitate is produced which is a brown solid. Therefore, there is a colour change from blue to brown.

Question 4

What pH is an alcohol?

Answer 4

7

Question 5

What pH is a phenol?

Answer 5

5-6. Due to there being some delocalisation across the C-O bond. This makes the ion more stable.

Question 6

What pH is a carboxylic acid?

Answer 6

3-4. There is delocalisation across both the C-O bonds. This produces the most stable ion and it is the most acidic substance.

Question 7

How can you tell if an alcohol is oxidised?

Answer 7

Orange potassium dichromate (VI) is reduced to green potassium dichromate (VI).

Question 8

How is an aldehyde produced?

Answer 8

A primary alcohol must be oxidised by acidified dichromate (VI). This can be heated by distillation.