Which of the following has the highest solubility product ?

Options

A. KOH
B. CsOH
C. LiOH
D. RbOH.

Explanation

To determine which of the following alkali metal hydroxides has the highest solubility product, we can follow these steps:

### Step 1: Understand the Concept of Solubility Product
The solubility product (Ksp) is a constant that indicates the solubility of a compound in water. For ionic compounds, a higher Ksp value means that the compound is more soluble in water.

### Step 2: Identify the Alkali Metal Hydroxides
The alkali metal hydroxides we need to consider are:
- Lithium hydroxide (LiOH)
- Sodium hydroxide (NaOH)
- Potassium hydroxide (KOH)
- Rubidium hydroxide (RbOH)
- Cesium hydroxide (CsOH)

### Step 3: Analyze the Trend of Solubility in Alkali Metals
As we move down the group of alkali metals in the periodic table, the size of the cation increases. This increase in size generally leads to an increase in solubility due to the weaker attraction between the larger cation and the hydroxide ion (OH⁻).

### Step 4: Determine the Order of Solubility
Based on the trend of increasing solubility down the group, we can arrange the hydroxides in order of increasing solubility:
1. LiOH (least soluble)
2. NaOH
3. KOH
4. RbOH
5. CsOH (most soluble)

### Step 5: Conclusion
From the analysis, we conclude that cesium hydroxide (CsOH) has the highest solubility product among the alkali metal hydroxides.

### Final Answer
The compound with the highest solubility product is **Cesium hydroxide (CsOH)**.

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