When copper is treated with dilute nitric acid, the gas evolved is

Options

A. `N_2`
B. `NO_2`
C. NO
D. `NH_3`

Answer

To solve the question "When copper is treated with dilute nitric acid, the gas evolved is?", we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are copper (Cu) and dilute nitric acid (HNO₃).

### Step 2: Write the Reaction
When copper reacts with dilute nitric acid, it forms copper nitrate (Cu(NO₃)₂), water (H₂O), and a gas. The reaction can be represented as:
\[ \text{Cu} + \text{HNO}_3 \rightarrow \text{Cu(NO}_3\text{)}_2 + \text{H}_2\text{O} + \text{Gas} \]

### Step 3: Determine the Gas Produced
In the case of dilute nitric acid reacting with copper, the gas produced is nitric oxide (NO). This is because nitric acid is a weak oxidizing agent in dilute form, leading to the formation of nitric oxide instead of nitrogen dioxide (NO₂).

### Step 4: Write the Balanced Equation
To balance the reaction, we need to ensure that the number of atoms of each element is the same on both sides of the equation. The balanced equation for the reaction of copper with dilute nitric acid is:
\[ 3 \text{Cu} + 8 \text{HNO}_3 \rightarrow 3 \text{Cu(NO}_3\text{)}_2 + 4 \text{H}_2\text{O} + 2 \text{NO} \]

### Step 5: Conclusion
From the balanced equation, we can conclude that the gas evolved when copper is treated with dilute nitric acid is nitric oxide (NO).

### Final Answer
The gas evolved is **Nitric Oxide (NO)**.

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