The order of basic strength of alkaline earth metal hydroxide is

Options

A. `Be(OH)_2gt Mg(OH)_2gt Ca(OH)_2gt Ba(OH)_2`
B. `Be(OH)_2 gt Mg(OH)_2 Ca(OH)_2 gt Ba(OH)_2`
C. `Ba(OH)_2 gt Ca(OH_2 gt Mg(OH)_2 gt Ba(OH)_2`
D. `Ba(OH)_2 gt Ca(OH)_2gt Be(OH)_2 gt Mg(OH)_2`

Answer

To determine the order of basic strength of alkaline earth metal hydroxides, we need to consider the trend in basicity as we move down the group in the periodic table. Here are the steps to analyze the order of basic strength:

### Step 1: Identify the Alkaline Earth Metals
The alkaline earth metals include Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), and Barium (Ba).

### Step 2: Understand Basic Strength
Basic strength of hydroxides generally increases as we move down a group in the periodic table. This is due to the increase in atomic size, which leads to a decrease in the lattice energy of the hydroxides and an increase in the solubility of the hydroxides in water.

### Step 3: Analyze the Hydroxides
- **Beryllium Hydroxide (Be(OH)₂)**: It is less basic due to the small size of Beryllium and its strong covalent character.
- **Magnesium Hydroxide (Mg(OH)₂)**: More basic than Beryllium Hydroxide but still not very basic.
- **Calcium Hydroxide (Ca(OH)₂)**: More basic than Magnesium Hydroxide.
- **Strontium Hydroxide (Sr(OH)₂)**: More basic than Calcium Hydroxide.
- **Barium Hydroxide (Ba(OH)₂)**: The most basic among these hydroxides due to its larger size and higher solubility.

### Step 4: Order the Basic Strength
Based on the analysis:
1. Barium Hydroxide (Ba(OH)₂) - most basic
2. Strontium Hydroxide (Sr(OH)₂)
3. Calcium Hydroxide (Ca(OH)₂)
4. Magnesium Hydroxide (Mg(OH)₂)
5. Beryllium Hydroxide (Be(OH)₂) - least basic

### Final Order
Thus, the order of basic strength of alkaline earth metal hydroxides is:
**Ba(OH)₂ > Sr(OH)₂ > Ca(OH)₂ > Mg(OH)₂ > Be(OH)₂**