Highly pure dilute solution of sodium in ammonia

Options

A. Shows blue colouration due to solvated electrons
B. Shows electrical conductivity due to both solvated electrons and solvated sodium ions
C. Shows red colouration due to solvated electrons but a bad conductor or electricity
D. Produces hydrogen gas or carbonate

Answer

To solve the question regarding the highly pure dilute solution of sodium in ammonia, we will analyze each statement provided in the options and determine their validity based on the chemistry of sodium and ammonia.

### Step-by-Step Solution:

1. **Understanding Sodium in Ammonia:**
- Sodium (Na) is an alkali metal that reacts with ammonia (NH₃) to form a solution that contains solvated electrons and sodium ions.

2. **Analyzing the First Statement:**
- The first statement claims that the solution shows blue coloration due to solvated electrons.
- When sodium dissolves in ammonia, it donates electrons that become solvated (surrounded by solvent molecules), which absorb blue light and emit a characteristic blue color.
- **Conclusion:** This statement is **true**.

3. **Analyzing the Second Statement:**
- The second statement mentions that the solution exhibits electrical conductivity due to both solvated electrons and solvated sodium ions.
- The presence of solvated electrons and sodium ions (Na⁺) in the solution allows it to conduct electricity effectively.
- **Conclusion:** This statement is also **true**.

4. **Analyzing the Third Statement:**
- The third statement suggests that the solution has a red coloration due to solvated electrons and is a bad conductor of electricity.
- This is incorrect because the solution is blue, not red, and it is a good conductor of electricity due to the presence of solvated electrons and ions.
- **Conclusion:** This statement is **false**.

5. **Analyzing the Fourth Statement:**
- The fourth statement claims that the solution produces hydrogen gas or carbonate.
- In a dilute solution of sodium in ammonia, there is no production of hydrogen gas or carbonate. The reaction primarily involves the formation of sodium amide (NaNH₂) and hydrogen gas is not produced in this context.
- **Conclusion:** This statement is **false**.

### Final Conclusion:
- The correct options are **A and B**. The solution shows blue coloration due to solvated electrons and exhibits electrical conductivity due to both solvated electrons and solvated sodium ions.