Which of the following bicarbonate does not exist in solid state?

Options

A. `NaHCO_(3)`
B. `KHCO_(3)`
C. `Ca(HCO_(3))_(2)`
D. `RbHCO_(3)`

Explanation

To determine which bicarbonate does not exist in solid state, we will analyze the given options one by one.

### Step-by-Step Solution:

1. **Understanding Bicarbonates**: Bicarbonates are salts that contain the bicarbonate ion (HCO3^-). They are typically formed from alkali metals and alkaline earth metals.

2. **Analyzing Each Option**:
- **A. Sodium Bicarbonate (NaHCO3)**: This compound is stable and exists in solid form as a white crystalline powder. It is commonly known as baking soda.
- **B. Potassium Bicarbonate (KHCO3)**: This compound is also stable and exists in solid form. It is used in various applications, including as a leavening agent.
- **C. Calcium Bicarbonate (Ca(HCO3)2)**: Calcium bicarbonate is not stable in solid form. It exists only in aqueous solution. When heated, it decomposes into calcium carbonate (CaCO3), carbon dioxide (CO2), and water (H2O).
- **D. Rubidium Bicarbonate (RbHCO3)**: This compound is stable and exists in solid form as well.

3. **Conclusion**: Based on the analysis, the bicarbonate that does not exist in solid state is **Calcium Bicarbonate (Ca(HCO3)2)**.

### Final Answer:
**C. Calcium Bicarbonate (Ca(HCO3)2)** does not exist in solid state.