Question

(a) Write IUPAC names of the following compounds:

             

                                  

(b) Write equations of the following chemical reactions:
(i) Phenol reacts with conc. ${\text{HN}}{{\text{O}}_{\text{3}}}$
(ii) Phenol reacts with zinc dust.

Answer 1

Hint: Whenever you are naming an organic compound, according to the IUPAC rules, find the longest carbon chain first. If you get two same long chains, then take the one in which the sum of positions of substituents will be minimum.

Complete step by step answer:
(a) (i) In this case, the longest carbon chain is propane. Also, in the second position of propane, there is an ether group joined. The joined ether group is called a methoxy group.
So, the name will be 2-methoxypropane.

(ii) In this case, the longest carbon chain is again propane. There is an OH group attached at one end which is an alcohol. So, we need to give priority for the carbon attached to this hydroxyl group. So, the numbering will start from the carbon attached with the hydroxyl group. And also, there is a methyl group attached at the second position of the chain.
So, the name of this compound is 2-methyl-propanol.

(b) (i) When concentrated nitric acid is treated with the phenol, we will get 2,4,6-trinitro phenol which is known as picric acid.

(ii) When we react phenol with zinc dust, the phenol gets reduced and we get benzene and ZnO as products.

Note: Whenever you are naming an organic compound, make sure the carbon chain you have selected is the longest one. Sometimes, you may think that it is a substituent group in some cases. But it will be the part of the longest chain. This is the common mistake which students may make in the naming.