consider the reaction below. nh4+ + h2o → nh3 + h3o+ which is an acid - conjugate base pair? o nh4+ and nh3…

Answer:

A. $NH_4^+$ and $NH_3$

Explanation:

Step1: Recall acid - conjugate base concept

An acid donates a proton ($H^+$) to form its conjugate base.

Step2: Analyze the reaction

In the reaction $NH_4^++H_2O\rightarrow NH_3 + H_3O^+$, $NH_4^+$ donates a proton to become $NH_3$. So $NH_4^+$ is the acid and $NH_3$ is its conjugate base.

Step3: Check other pairs

• For $NH_4^+$ and $H_3O^+$, they are not an acid - conjugate base pair related to each other in this reaction.
• For $H_2O$ and $NH_3$, they are not an acid - conjugate base pair.
• For $H_2O$ and $H_3O^+$, $H_2O$ is the base and $H_3O^+$ is its conjugate acid, not the pair asked in the question.