When marble chips are treated with HCI , which of the following gas is liberated?

Options

A. `CO_2`
B. `O_2`
C. `CO`
D. `NO_2`

Answer

To solve the question of which gas is liberated when marble chips are treated with hydrochloric acid (HCl), we can follow these steps:

### Step 1: Identify the Composition of Marble Chips
Marble chips are primarily composed of calcium carbonate (CaCO3).

### Step 2: Write the Reaction Equation
When calcium carbonate reacts with hydrochloric acid, the chemical reaction can be represented as:
\[ \text{CaCO}_3 (s) + 2 \text{HCl} (aq) \rightarrow \text{CaCl}_2 (aq) + \text{H}_2\text{O} (l) + \text{CO}_2 (g) \]

### Step 3: Analyze the Products
From the reaction, we can see that the products formed are:
- Calcium chloride (CaCl2)
- Water (H2O)
- Carbon dioxide (CO2)

### Step 4: Identify the Gas Liberated
The gas that is liberated during this reaction is carbon dioxide (CO2).

### Step 5: Conclusion
Thus, when marble chips are treated with hydrochloric acid, the gas that is liberated is carbon dioxide (CO2).

### Final Answer
The correct answer is carbon dioxide (CO2).

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