Illustrate the following name reactions by giving example:

Clemmensen's reduction

Give reasons for the following :

Treatment with benzaldehyde with $\mathrm{HCN}$ gives a mixture of two isomers which cannot be separated even by careful fractional distillations.

Give reasons for the following :

Sodium bisulphite is used for the purification of aldehydes and ketones.

Write the steps and conditions involved in the following conversion:

Acetophenone to $2$-Phenyl-$2$-butanol.

Write the steps and conditions involved in the following conversion:

Propene to acetone.

Write the steps and conditions involved in the following conversion:

Acetophenone to $2$-Phenyl-$2$-butanol

Write the steps and conditions involved in the following conversion:

Propene to acetone

How would you bring about the following conversion:

Propanal to Butanone

How would you bring about the following conversion:

Benzaldehyde to Benzophenone