When dry ammonia gas is passed over heated sodium (out of contact of air) the product formed is

Options

A. Sodium hydride
B. Sodium nitride
C. Sodamide
D. Sodium cynamide

Explanation

To determine the product formed when dry ammonia gas is passed over heated sodium (in the absence of air), we can follow these steps:

### Step 1: Understand the Reactants
We have two reactants: dry ammonia gas (NH3) and heated sodium (Na). It's important to note that the sodium is heated and out of contact with air, which prevents any reaction with oxygen or nitrogen from the air.

**Hint:** Identify the state and conditions of the reactants to understand their behavior during the reaction.

### Step 2: Identify the Reaction
When dry ammonia is passed over heated sodium, a chemical reaction occurs. Sodium reacts with ammonia to form sodium amide (NaNH2) and hydrogen gas (H2).

**Hint:** Look for common reactions between alkali metals and ammonia to predict the products.

### Step 3: Write the Balanced Chemical Equation
The reaction can be represented as follows:
\[ 2 \text{Na} + 2 \text{NH}_3 \rightarrow 2 \text{NaNH}_2 + \text{H}_2 \]
This shows that two moles of sodium react with two moles of ammonia to produce two moles of sodium amide and one mole of hydrogen gas.

**Hint:** Ensure that the number of atoms of each element is the same on both sides of the equation for it to be balanced.

### Step 4: Identify the Product
From the balanced equation, we can see that the main product formed is sodium amide (NaNH2), along with hydrogen gas (H2).

**Hint:** Focus on the main product of the reaction, which is typically the compound that is formed in the greatest quantity.

### Step 5: Conclusion
The product formed when dry ammonia gas is passed over heated sodium is sodium amide (NaNH2).

**Final Answer:** Sodium amide (NaNH2)

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