Question

select the correct answer. which statement correctly relates two substances in this chemical equation? nh₃ + h₂o ⇌ oh⁻ + nh₄⁺ a. h₂o is the conjugate base of oh⁻. b. h₂o is the conjugate acid of nh₃. c. nh₄⁺ is the conjugate acid of nh₃. d. nh₃ is the conjugate acid of nh₄⁺. e. oh⁻ is the conjugate base of nh₃.

Explanation:

Step1: Recall conjugate - acid base pair concept

In an acid - base reaction, a conjugate acid is formed when a base accepts a proton ($H^+$), and a conjugate base is formed when an acid donates a proton.

Step2: Analyze the given reaction

In the reaction $NH_3 + H_2O
ightleftharpoons OH^-+NH_4^+$, $NH_3$ (a base) accepts a proton from $H_2O$ to form $NH_4^+$. So, $NH_4^+$ is the conjugate acid of the base $NH_3$.

Step3: Check other options

• Option A: The conjugate acid of $OH^-$ is $H_2O$, not the other way around.
• Option B: $H_2O$ is not the conjugate acid of $NH_3$.
• Option D: $NH_3$ is a base and $NH_4^+$ is its conjugate acid, not the other way around.
• Option E: $OH^-$ is not the conjugate base of $NH_3$. The conjugate base of $NH_3$ would be formed if $NH_3$ donated a proton (which is not common for $NH_3$ in this context), and $OH^-$ is formed from the dissociation of $H_2O$ in this reaction.

Answer:

C. $NH_4^+$ is the conjugate acid of $NH_3$.