Which of the following is the strongest base ?

Options

A. NaOH
B. KOH
C. `Ca(OH)_(2)`
D. `Mg(OH)_(2)`

Explanation

To determine which of the following is the strongest base among the given options, we can analyze the hydroxides of the alkali and alkaline earth metals provided:

1. **Identify the Compounds**:
- M: Sodium Hydroxide (NaOH)
- B: Potassium Hydroxide (KOH)
- C: Calcium Hydroxide (Ca(OH)₂)
- D: Magnesium Hydroxide (Mg(OH)₂)

2. **Classify the Hydroxides**:
- Sodium Hydroxide (NaOH) and Potassium Hydroxide (KOH) are hydroxides of alkali metals.
- Calcium Hydroxide (Ca(OH)₂) and Magnesium Hydroxide (Mg(OH)₂) are hydroxides of alkaline earth metals.

3. **Understand Basicity**:
- The basicity of hydroxides generally increases down the group in the periodic table.
- Alkali metal hydroxides (like NaOH and KOH) are known to be strong bases because they dissociate completely in water to release hydroxide ions (OH⁻).
- Alkaline earth metal hydroxides (like Ca(OH)₂ and Mg(OH)₂) are less soluble in water compared to alkali metal hydroxides, and thus, they are generally weaker bases.

4. **Compare the Strength of Bases**:
- Among the alkali metal hydroxides, KOH is stronger than NaOH because potassium is more electropositive than sodium, leading to a greater tendency to release OH⁻ ions.
- Between the alkaline earth metal hydroxides, Ca(OH)₂ is stronger than Mg(OH)₂ due to the higher solubility and greater dissociation in water.

5. **Conclusion**:
- Since alkali metal hydroxides are stronger bases than alkaline earth metal hydroxides, and KOH (potassium hydroxide) is stronger than NaOH, we conclude that KOH is the strongest base among the given options.

**Final Answer**: The strongest base among the given options is **Potassium Hydroxide (KOH)**.

---