Which of the following order of basic strength is correct ?

Options

A. `NH_(3) lt NH_(2)OH lt NH_(3) lt NH_(2) -NH_(2)`
B. `NH_(2)OH lt HN_(3) lt NH_(2)-NH_(2) lt NH_(3)`
C. `HN_(3) lt NH_(3) lt NH_(2)OH lt NH_(2)-NH_(2)`
D. `HN_(3) lt NH_(2)OH lt NH_(2)-NH_(2) lt NH_(3)`

Explanation

To determine the correct order of basic strength among the given compounds, we will analyze each compound step by step based on the presence of lone pairs of electrons and the stability of the resulting cations upon protonation.

### Step 1: Identify the Compounds
We have four compounds to consider:
1. Ammonia (NH3)
2. Hydrazine (N2H4)
3. Hydroxylamine (NH2OH)
4. Hydrazoic acid (N3H)

### Step 2: Analyze Basicity of Ammonia (NH3)
- Ammonia has one nitrogen atom with one lone pair of electrons.
- When ammonia accepts a proton (H+), it forms the ammonium ion (NH4+).
- The NH4+ ion is relatively stable due to the tetrahedral geometry and the complete octet of nitrogen.

### Step 3: Analyze Basicity of Hydrazine (N2H4)
- Hydrazine has two nitrogen atoms, each with one lone pair of electrons, giving a total of two lone pairs.
- However, when hydrazine accepts a proton, it forms the hydrazinium ion (N2H5+).
- The stability of N2H5+ is less than that of NH4+ because the positive charge is shared between two nitrogen atoms, making it less stable than NH4+.

### Step 4: Compare Basicity of Ammonia and Hydrazine
- Although hydrazine has more lone pairs, the stability of the resulting cation (N2H5+) is less than that of ammonium (NH4+).
- Therefore, ammonia (NH3) is more basic than hydrazine (N2H4).

### Step 5: Analyze Basicity of Hydroxylamine (NH2OH)
- Hydroxylamine has a nitrogen atom with one lone pair and an -OH group.
- The -OH group exerts a -I (inductive) effect, which decreases the electron density on nitrogen, making it less basic.
- Thus, hydroxylamine is less basic than both ammonia and hydrazine.

### Step 6: Analyze Basicity of Hydrazoic Acid (N3H)
- Hydrazoic acid is a weak base due to the presence of nitrogen atoms and the overall structure.
- It does not have a significant lone pair available for protonation, making it the weakest base among the four.

### Step 7: Summarize the Order of Basic Strength
Based on the analysis:
1. Ammonia (NH3) - Most basic
2. Hydrazine (N2H4)
3. Hydroxylamine (NH2OH) - Less basic
4. Hydrazoic acid (N3H) - Weakest base

### Final Order of Basic Strength
The correct order of basic strength is:
**NH3 > N2H4 > NH2OH > N3H**