`LiHCO_(3)` and `Ca(HCO_(3))_(2)` are not found in solid state .

Explanation

To determine whether the statement "LiHCO₃ and Ca(HCO₃)₂ are not found in solid state" is correct, we can analyze the properties of these compounds step by step.

### Step 1: Understand the Compounds
- **LiHCO₃**: Lithium bicarbonate
- **Ca(HCO₃)₂**: Calcium bicarbonate

### Step 2: Analyze Lattice Enthalpy and Hydration Enthalpy
- **Lattice Enthalpy**: This is the energy required to separate one mole of a solid ionic compound into its gaseous ions. Higher lattice enthalpy indicates a more stable solid structure.
- **Hydration Enthalpy**: This is the energy released when gaseous ions dissolve in water to form an aqueous solution. Higher hydration enthalpy indicates that the ions are more stable in solution.

### Step 3: Compare Lattice and Hydration Enthalpy
- In the case of lithium and calcium bicarbonates, the lattice enthalpy is relatively low compared to their hydration enthalpy. This means that when these compounds are formed, the energy released during hydration is greater than the energy required to maintain the solid structure.

### Step 4: Consider Charge Density
- Lithium (Li⁺) and calcium (Ca²⁺) have high charge densities. This means they can attract water molecules strongly, leading to a greater hydration enthalpy. The high charge density of these cations contributes to the stability of the ions in solution rather than in the solid state.

### Step 5: Conclusion
- Since the lattice enthalpy is less than the hydration enthalpy for both lithium bicarbonate and calcium bicarbonate, these compounds do not exist in the solid state but rather in solution.

### Final Answer
The statement is correct: LiHCO₃ and Ca(HCO₃)₂ are not found in solid state.

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