Assertion: `KHCO_(3)` can not be obtained by solvay process.
Reason: `KHCO_(3)` is less soluble than `NaHCO_(3)`

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion
C. If Assertion is True but the Reason is False
D. If both Assertion & Reason are False

Explanation

To solve the question, we need to analyze the assertion and the reason given:

**Assertion:** `KHCO3` cannot be obtained by the Solvay process.

**Reason:** `KHCO3` is less soluble than `NaHCO3`.

### Step-by-Step Solution:

1. **Understanding the Solvay Process:**
- The Solvay process is primarily used to produce sodium bicarbonate (`NaHCO3`) from sodium chloride (`NaCl`), ammonia (`NH3`), carbon dioxide (`CO2`), and water (`H2O`).
- The process involves the reaction of sodium chloride with ammonia and carbon dioxide to form sodium bicarbonate, which is then precipitated out.

2. **Analyzing the Assertion:**
- The assertion states that `KHCO3` cannot be obtained by the Solvay process.
- The Solvay process is specifically designed for sodium compounds, and while it can produce sodium bicarbonate, it does not produce potassium bicarbonate (`KHCO3`).
- Therefore, the assertion is **correct**.

3. **Analyzing the Reason:**
- The reason states that `KHCO3` is less soluble than `NaHCO3`.
- To compare the solubility, we need to consider the ionic sizes of potassium (`K+`) and sodium (`Na+`).
- Potassium ions are larger than sodium ions. According to Fajans' rules, larger cations tend to have a lower charge density, which can lead to increased covalent character in their compounds.
- However, `KHCO3` is actually more soluble than `NaHCO3` in water due to the ionic nature of potassium compounds.
- Therefore, the reason is **incorrect**.

4. **Conclusion:**
- The assertion is true, and the reason is false.
- Thus, the correct answer is that the assertion is correct, but the reason is incorrect.

### Final Answer:
- Assertion is true, Reason is false.