Question

The conjugate acid of $N{{H}_{2}}^{-}$ is:
A. $N{{H}_{3}}$
B. $N{{H}^{2-}}$
C. $N{{H}_{4}}^{+}$
D. ${{N}_{3}}^{-}$

Answer 1

Hint: $N{{H}_{2}}^{-}$ is referred to as amides and the IUPAC name sanctioned for this anion is Azanide. A conjugate acid is formed when an acid donates its proton to base. This theory is known as acid base theory.

Complete step by step answer:
Bronsted-lowry theory is basically an acid base reaction theory which has given a fundamental concept that when a base reacts with an acid , the acid forms its conjugate base and the base forms its conjugate acid.
In this theory, they have defined acids and bases by the way they react with each other. Their definitions were expressed in terms of equilibrium expression.
\[HA+B\rightleftharpoons {{A}^{-}}+H{{B}^{+}}\]
Where, $HA$ is an acid and ${{A}^{-}}$ is conjugate base
$B$ is the base $H{{B}^{+}}$ is a conjugate acid.
In this reaction, an acid loses its electron to become its conjugate base and the base accepts the electron to become its conjugate acid.
$N{{H}_{2}}^{-}+{{H}^{+}}\to N{{H}_{3}}$
Where, $N{{H}_{2}}^{-}$ is a base, ${{H}^{+}}$ is a proton and $N{{H}_{3}}$ is a conjugate acid.
Here, the base that is $N{{H}_{2}}^{-}$ accepts a proton that gives conjugate acid that is $N{{H}_{3}}$ .

So, the correct answer is Option A .

Additional information:
Ammonia is a colourless gas that is composed of nitrogen and hydrogen. It is a stable binary hydride compound. It is used in agriculture as fertilizers. It is also used in the purification of water supplies.
Conjugate acid is formed when an acid donates a proton or when it loses a hydrogen ion.

Note: When a base accepts a proton it gives conjugate acid as a product and when acid donates a proton it gives conjugate base as a product. In this question, $N{{H}_{2}}^{-}$ is a base that accepts protons to give ammonia as a conjugate acid.