Which among the following is not a base?

Options

A. NaOH
B. KOH
C. `NH_(4)OH`
D. `C_(2)H_(5)OH`

Explanation

To determine which among the given options is not a base, we need to understand the definition of a base. A base is a substance that can accept protons (H⁺ ions) or donate hydroxide ions (OH⁻) in a solution.

### Step-by-Step Solution:

1. **Identify the Definition of a Base**:
- A base is a substance that produces hydroxide ions (OH⁻) when dissolved in water.

2. **Examine the Given Options**:
- Let's analyze the compounds mentioned:
- **NaOH (Sodium Hydroxide)**: This is a strong base as it dissociates in water to produce Na⁺ and OH⁻ ions.
- **KOH (Potassium Hydroxide)**: Similar to NaOH, it is also a strong base that produces OH⁻ ions in solution.
- **NH₄OH (Ammonium Hydroxide)**: This is a weak base that also produces OH⁻ ions when dissolved in water.
- **C₂H₅OH (Ethanol)**: This is an organic compound known as ethanol, which contains an -OH group. However, this -OH group is part of an alcohol and does not produce OH⁻ ions in the same way that bases do.

3. **Conclusion**:
- Among the options, C₂H₅OH (Ethanol) is not a base because it does not produce hydroxide ions in solution. Instead, it contains an -OH group that is characteristic of alcohols, not bases.

### Final Answer:
C₂H₅OH (Ethanol) is not a base.

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