A highly pure dilute solution of sodium in liquid ammonia:

Options

A. Shows blue colour
B. Exhibits electrical conductivity
C. Produces sodium amide
D. Produces hydrogen gas

Answer

To solve the question regarding a highly pure dilute solution of sodium in liquid ammonia, we will analyze each of the given options step by step.

### Step 1: Understanding the Solution
A highly pure dilute solution of sodium in liquid ammonia contains sodium metal dissolved in ammonia. When sodium is added to liquid ammonia, it dissociates and forms solvated electrons and sodium cations.

**Hint:** Remember that sodium in ammonia leads to the formation of solvated electrons.

### Step 2: Analyzing the Color
The presence of solvated electrons in the solution is responsible for the characteristic blue color of the solution. These electrons absorb certain wavelengths of light, giving the solution its blue appearance.

**Hint:** Think about what causes the blue color in solutions with solvated electrons.

### Step 3: Electrical Conductivity
The solution exhibits electrical conductivity due to the presence of free-moving ions (sodium cations and solvated electrons). These charged particles can carry electric current through the solution.

**Hint:** Consider the role of ions in conducting electricity in solutions.

### Step 4: Formation of Sodium Amide and Hydrogen Gas
The options mention the production of sodium amide and hydrogen gas. However, this reaction typically requires a catalyst (like platinum black or iron oxide) to occur. In the absence of such a catalyst, sodium amide and hydrogen gas will not be produced.

**Hint:** Recall the conditions required for the formation of sodium amide and hydrogen gas.

### Step 5: Conclusion
Based on the analysis:
- The solution shows a blue color (True).
- The solution exhibits electrical conductivity (True).
- The solution does not produce sodium amide and hydrogen gas without a catalyst (False).

Thus, the correct options are:
- **A: It shows blue color.**
- **B: It exhibits electrical conductivity.**

**Final Answer:** The correct options are A and B.