Which among the following is the strongest base?

Options

A. `Be(OH)_(2)`
B. `Mg(OH)_(2)`
C. `Ba(OH)_(2)`
D. `Sr(OH)_(2)`

Answer

To determine which among the given options is the strongest base, we need to analyze the hydroxides of alkaline earth metals (Group 2 elements). The alkaline earth metals include Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).

### Step-by-Step Solution:

1. **Identify the Hydroxides**: The hydroxides of the alkaline earth metals we are considering are Be(OH)₂, Mg(OH)₂, Ca(OH)₂, Sr(OH)₂, and Ba(OH)₂.

2. **Understand Basicity Trend**: The basicity of hydroxides of alkaline earth metals increases down the group. This is due to the increase in atomic size, which leads to a decrease in ionization energy. As the size of the metal ion increases, the bond between the metal and hydroxide ion becomes weaker, making it easier to dissociate and release OH⁻ ions.

3. **Evaluate Each Hydroxide**:
- **Be(OH)₂**: This is amphoteric, meaning it can react with both acids and bases, but it is not a strong base.
- **Mg(OH)₂**: This is a weak base and does not dissociate completely in water.
- **Ca(OH)₂**: This is a stronger base than Mg(OH)₂ but still not the strongest.
- **Sr(OH)₂**: This is stronger than Ca(OH)₂.
- **Ba(OH)₂**: This is the strongest base among the alkaline earth metal hydroxides.

4. **Conclusion**: Based on the trend of increasing basicity down the group, Barium hydroxide (Ba(OH)₂) is the strongest base among the given options.

### Final Answer:
The strongest base among the options is **Barium hydroxide (Ba(OH)₂)**.