The strongest base amongst the following in (In aqueous state):

Options

A. `NH_(3)`
B. `C_(2)H_(5)NH_(2)`
C. `(C_(2)H_(5))_(2)N`
D. `(C_(2)H_(5))_(3)N`

Answer

To determine the strongest base in aqueous solution among the given compounds: NH3 (ammonia), C2H5NH2 (ethylamine), C2H5NH(C2H5) (diethylamine), and C2H5N(C2H5)2 (triethylamine), we can analyze the basicity of each compound step by step.

### Step-by-Step Solution:

1. **Understanding Basicity**: Basicity refers to the ability of a compound to accept protons (H+ ions). In the context of amines, basicity increases with the availability of the lone pair of electrons on the nitrogen atom to bond with protons.

2. **Analyzing NH3 (Ammonia)**:
- Ammonia has one alkyl group (hydrogen) attached to the nitrogen.
- The lone pair on nitrogen is available for protonation, but it is not significantly stabilized by any electron-donating groups.
- **Basicity**: Moderate.

3. **Analyzing C2H5NH2 (Ethylamine)**:
- Ethylamine has one ethyl group attached to the nitrogen.
- The ethyl group is an electron-donating group, which increases the electron density on nitrogen and enhances its ability to accept protons.
- **Basicity**: Higher than NH3.

4. **Analyzing C2H5NH(C2H5) (Diethylamine)**:
- Diethylamine has two ethyl groups attached to the nitrogen.
- The presence of two electron-donating ethyl groups significantly increases the electron density on nitrogen, making it more basic than ethylamine and ammonia.
- **Basicity**: Higher than C2H5NH2.

5. **Analyzing C2H5N(C2H5)2 (Triethylamine)**:
- Triethylamine has three ethyl groups attached to the nitrogen.
- While it has the highest number of electron-donating groups, the steric hindrance around the nitrogen atom can make it less available for protonation compared to diethylamine.
- **Basicity**: Lower than diethylamine but still higher than ammonia and ethylamine.

6. **Ranking the Basicity**:
- Based on the analysis, the order of basicity in aqueous solution is:
- C2H5NH(C2H5) (Diethylamine) > C2H5N(C2H5)2 (Triethylamine) > C2H5NH2 (Ethylamine) > NH3 (Ammonia).

7. **Conclusion**:
- The strongest base among the given compounds in aqueous state is **C2H5NH(C2H5)** (Diethylamine).