What is formed when calcium carbide reacts with heavy water?

Options

A. `C_(2)D_(2)`
B. `CaD_(2)`
C. `Ca_(2)D_(2)O`
D. `CD_(2)`

Answer

To determine what is formed when calcium carbide reacts with heavy water, we can follow these steps:

### Step 1: Understand the Reactants
Calcium carbide (CaC2) is a chemical compound that reacts with water to produce acetylene gas and calcium hydroxide. Heavy water (D2O) is water in which both hydrogen atoms are replaced by deuterium, an isotope of hydrogen.

### Step 2: Write the Reaction with Normal Water
When calcium carbide reacts with normal water (H2O), the reaction can be written as:
\[ \text{CaC}_2 + 2 \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{C}_2\text{H}_2 \]
This reaction produces calcium hydroxide (Ca(OH)2) and acetylene gas (C2H2).

### Step 3: Adapt the Reaction for Heavy Water
Since heavy water behaves similarly to normal water, we can replace H2O with D2O in the reaction:
\[ \text{CaC}_2 + 2 \text{D}_2\text{O} \rightarrow \text{Ca(OD)}_2 + \text{C}_2\text{D}_2 \]
In this reaction, calcium deuteroxide (Ca(OD)2) is formed along with deuterated acetylene (C2D2).

### Step 4: Identify the Products
From the adapted reaction, we can see that the products are:
1. Calcium deuteroxide (Ca(OD)2)
2. Deuterated acetylene (C2D2)

### Step 5: Choose the Correct Option
Among the given options:
1. C2D2 (Correct)
2. Calcium deuterium (Incorrect)
3. Ca2D2O (Incorrect)
4. Cd2 (Incorrect)

The correct answer is **C2D2**.

### Final Answer
When calcium carbide reacts with heavy water, the product formed is **C2D2**.

---