Among the following compounds, the most basic compound is :

Options

A.
B.
C.
D.

Explanation

To determine which compound among the given options is the most basic, we need to analyze the availability of the lone pairs of electrons in each compound. The basic strength of a compound is directly proportional to how readily it can donate its lone pair of electrons. Here’s a step-by-step solution:

### Step 1: Understand Basicity
Basicity refers to the ability of a compound to accept protons (H⁺ ions) or donate lone pairs of electrons. The more available the lone pairs are for donation, the stronger the base.

**Hint:** Recall that basicity is linked to the availability of lone pairs for donation.

### Step 2: Analyze Each Compound
1. **First Compound:**
- Contains nitrogen with lone pairs involved in resonance.
- The lone pairs are delocalized and not readily available for donation.
- **Conclusion:** This compound is not very basic.

2. **Second Compound:**
- Similar to the first, it has nitrogen with lone pairs involved in resonance.
- Again, the lone pairs are not available for donation due to resonance.
- **Conclusion:** This compound is also not very basic.

3. **Third Compound:**
- Contains oxygen with two lone pairs.
- Oxygen is more electronegative than nitrogen, which means it holds onto its electrons more tightly.
- While it has lone pairs, the high electronegativity reduces the availability for donation.
- **Conclusion:** This compound is less basic than nitrogen.

4. **Fourth Compound:**
- Contains nitrogen with one lone pair.
- Nitrogen is less electronegative than oxygen, meaning it can donate its lone pair more readily.
- The lone pair on nitrogen is more available for donation compared to the lone pairs on oxygen.
- **Conclusion:** This compound is the most basic among the options.

### Step 3: Final Decision
After analyzing the availability of lone pairs and considering the electronegativity of the atoms involved, we conclude that the fourth compound (with nitrogen) is the most basic.

**Final Answer:** The most basic compound is the fourth option.

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