The cojugate acid of `NH_2^-` is

Options

A. `NH_3`
B. `NH_2OH`
C. `NH_4^+`
D. `N_3H`

Explanation

To find the conjugate acid of \( \text{NH}_2^- \), we can follow these steps:

### Step 1: Understand the Concept of Conjugate Acids and Bases
A conjugate acid is formed when a base accepts a proton (\( \text{H}^+ \)). In other words, the conjugate acid of a base is the species that results when the base gains a proton.

### Step 2: Identify the Base
In this case, the base is \( \text{NH}_2^- \) (the amide ion).

### Step 3: Add a Proton to the Base
To find the conjugate acid, we need to add a proton (\( \text{H}^+ \)) to \( \text{NH}_2^- \):
\[ \text{NH}_2^- + \text{H}^+ \rightarrow \text{NH}_3 \]

### Step 4: Determine the Resulting Species
When \( \text{NH}_2^- \) accepts a proton, it forms \( \text{NH}_3 \) (ammonia). The negative charge on \( \text{NH}_2^- \) is neutralized by the positive charge of the proton, resulting in a neutral molecule \( \text{NH}_3 \).

### Conclusion
Thus, the conjugate acid of \( \text{NH}_2^- \) is \( \text{NH}_3 \).

### Final Answer
The conjugate acid of \( \text{NH}_2^- \) is \( \text{NH}_3 \).

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