Question

What happens when:
Phenol is treated with Zn dust?
Write chemical equations in support of your answer.

Answer 1

Hint: Distillation of phenol with zinc-dust gives benzene and ZnO as a side-product. The reaction proceeds as follows: - The phenol gets converted into phenoxide ion and thus the released proton accepts an electron from Zn forming hydrogen radical. because of the heating, there's homolytic fission of C of the phenyl ring and O−.

Complete answer:
When phenol is heated with zn dust reduction of phenol occurs and it gets converted into Benzene with ZnO as a by-product.
Here's the reaction:
Phenol+ Zn $\Rightarrow$ Benzene + ZnO
And here's the detailed mechanism;
Zn shows an oxidation state of +2.
The phenol gets converted into phenoxide ion and the proton thus released accepts an electron from Zn forming H radical.
Also thanks to the heating there's homolytic fission of C of phenyl ring and O-
The O- thus formed accepts an electron from Zn and forms an oxide ion.
In this way zinc forms flowers of zinc and phenyl radical thus forms a bond with H radical.
However, the yield of this reaction used for benzene formation is lower.
Zinc dust is used to manufacture paints and coatings that resist corrosion when applied to structures or surfaces that are vulnerable to harsh environmental conditions.

Note:
Most zinc is used to galvanise other metals, like iron, to prevent rusting. Galvanised steel is used for car bodies, streetlight posts, safety barriers and suspension bridges. Large quantities of zinc are used to produce die-castings, which are important within the car , electrical and hardware industries.