Question

The conjugate base of hydrazoic acid is:

$$A.{\text{ }}{N^{ - 3}} \\\ B.{\text{ }}N_3^ - \\\ C.{\text{ }}N_2^ - \\\ D.{\text{ }}HN_3^ - \\\$$

Answer 1

In order to solve the given problem first we will see the brief discussion of the conjugate base. In order to solve the problem we will see the chemical formula for the hydrazoic acid. And we will also see the basic method in which the conjugate base is made from the corresponding acid. On the basis of this discussion we will see the formation of conjugate base from the hydrazoic acid and will select the corresponding option out of the given four.

Complete step by step answer:
A more general meaning is that a conjugate base is the base member of a pair of compounds that turn into each other by obtaining or losing a proton. The conjugate base is able to obtain or absorb a proton in a chemical reaction. The proton or hydrogen is donated by the conjugate acid in the reaction. A conjugate base comprises one H atom less and one charge greater than the acid that created it. The conjugate base of water is a hydroxide ion.
The chemical formula for hydrazoic acid is ${N_3}H$ .
In order to form a conjugate base from the acid the basic process is to remove an ${H^ + }$ ion from the given acid.
So, in order to find the conjugate base of the hydrazoic acid we will remove the ${H^ + }$ ion from the acid.
In the chemical formula of hydrazoic acid we can see that there are three nitrogen atoms and one hydrogen atom. So after removal of hydrogen ion we are left with:
${N_3}H = N_3^ - + {H^ + }$
So, we are left with the conjugate base $N_3^ -$ . This conjugate base is known as azide ion.
Hence, the conjugate base of hydrazoic acid is $N_3^ -$ .
So, the correct answer is “Option B”.

Note: In order to solve the given problem students must remember the basic method of formation of conjugate acid and conjugate base. In the formation of the conjugate base only one of the hydrogen atoms with positive charge is removed, so the overall charge in this case was -1 on the overall conjugate base. In the similar way when we have to form conjugate acid from the base we have to remove one $O{H^ - }$ ion from the base.