Which of the following have been arranged correctly in order of increasing basic strength?

Options

A. `C_(6)H_(5) N(CH_(3))_(2) lt C_(6)H_(5) NH_(2)`
B. `NH_(2)ltOHltI`
C. `(CH_(3))_(3) Nlt CH_(3)NH_(2) lt(CH_(3))_(2)NH`
D. `NH_(2) OH lt N_(2)H_(4) lt NH_(3)`

Answer

To determine the correct order of increasing basic strength among the given compounds, let's analyze each option step by step.

### Step 1: Understanding Basic Strength
Basic strength refers to the ability of a compound to donate a pair of electrons to a proton (H+). The more readily a compound can donate its electrons, the stronger the base it is.

### Step 2: Analyze the Given Compounds
We have four groups to analyze:
1. N,N-dimethyl aniline
2. Aniline
3. NH2−, OH−, I−
4. NH2, OH, and NH3

### Step 3: Compare N,N-Dimethyl Aniline and Aniline
- **N,N-Dimethyl Aniline** has two methyl groups (CH3) attached to the nitrogen, which provide a +I (inductive) effect, increasing the electron density on the nitrogen atom.
- **Aniline** has a hydrogen atom attached to the nitrogen, which does not provide the same electron-donating effect as the methyl groups.
- Therefore, N,N-dimethyl aniline is more basic than aniline.

### Step 4: Analyze NH2−, OH−, and I−
- **NH2− (Amide ion)** is a stronger base than **OH− (Hydroxide ion)** because nitrogen is less electronegative than oxygen, making NH2− more willing to donate its electrons.
- **I− (Iodide ion)** is the weakest base among these because it is a large ion and is less stable when it comes to donating electrons.
- The correct order of basic strength is: NH2− > OH− > I−.

### Step 5: Analyze NH2, OH, and NH3
- **NH2 (Hydrazine)** is more basic than **OH** because the nitrogen atom is less electronegative than oxygen, allowing it to donate electrons more readily.
- **NH3 (Ammonia)** is the most basic of the three because it has no electron-withdrawing groups that would decrease its electron density.
- Therefore, the order of basic strength is: NH3 > NH2 > OH.

### Step 6: Conclusion
From the analysis, we conclude that the correct arrangement of increasing basic strength is:
- **N,N-Dimethyl Aniline > Aniline**
- **NH2− > OH− > I−**
- **NH3 > NH2 > OH**

The fourth option is the correct arrangement of increasing basic strength.

### Final Answer
The correct order of increasing basic strength is:
**NH2, OH, NH3** (NH3 is the most basic, followed by NH2, and OH is the least basic).

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