Question 1

What is the cumene process for preparing phenol?

Accepted Answer

Benzene reacts with propene in the presence of anhydrous aluminium chloride to form cumene. Cumene is oxidised by oxygen in the presence of cobalt(II) salts to cumene hydroperoxide, which is then treated with dilute sulphuric acid to give phenol and acetone.

Question 2

Why are phenol and acetone formed in equimolar amounts?

Accepted Answer

One molecule of cumene hydroperoxide cleaves into one molecule of phenol and one molecule of acetone. Therefore, the theoretical product ratio is 1:1.

Question 3

What is the alternative route to phenol?

Accepted Answer

Benzene undergoes sulphonation with concentrated sulphuric acid to form benzenesulphonic acid. Alkali fusion with molten sodium hydroxide near 300 °C replaces the sulphonate group to form sodium phenoxide, which is then acidified to produce phenol and a sodium salt.

Question 4

How is oxygen attached in phenol?

Accepted Answer

Phenol has the formula C6H5OH. Its oxygen is directly bonded to one of the sp2-hybridised aromatic carbon atoms, and the hydrogen is bonded to oxygen. It is not made by simple addition of water to benzene.

Question 5

What does the benzene ring look like in the 3D model?

Accepted Answer

The six carbon atoms form a planar aromatic ring, with one hydrogen on each unsubstituted carbon. Delocalised pi electron density is shown above and below the ring plane rather than as fixed alternating double bonds.

Phenol Preparation 3D: Benzene se Phenol ke Routes

About this lab

Practice