Oxidisation Reactions Of Alcohols

Question 1

Conditions for the oxidation of alcohols

Answer 1

A reagent of potassium dichromate(VI) and dilute sulphuric acid are used.

Question 2

Oxidation of primary alcohol equations 1 & 2

What are the products?

Answer 2

REACTION 1: ROH + [O] —> RCHO + H2O
Aldehyde

REACTION 2: RCHO + [O] —> RCOOH
Carboxylic acid

Question 3

Equation for the oxidation of secondary alcohols

What is the product?

Answer 3

R(OH)R + [O] —> R(C=O)R + H2O

A Ketone

Question 4

What are some tests for aldehydes?

Answer 4

Benedict’s/ Fehling’s solution
Tollens reagent

Potassium dichromate and sulfuric acid
- also positive for just alcohols

Question 5

Colour change for Benedict’s/Fehling’s what does positive mean

Answer 5

Blue solution forms a red ppt

Aldehyde is present

Question 6

What does Tollens reagent test for?

What does positive show?

Answer 6

Aldehydes

Positive is where a silver mirror forms

Question 7

What does it mean if it is not a neutral organic compound

Answer 7

It is an aldehyde, ketone or alcohol

Not a carboxylic acid

Question 8

Colour change for potassium dichromate and sulphuric acid is positive?
WHAT DOES IT SHOW?

Answer 8

Orange —> green

Aldehyde present or alcohol group
Both can be oxidised further