Lead is not affected by dil . HCl in cold , because

Options

A. Pb is less electronegative than H
B. PbO film is formed which resists chemical attack by acid.
C. A protective coating of `PbCl_2` is formed on Pb surface
D. `PbO_2`of film is always present on Pb surface , which resists chemical attack

Answer

To solve the question "Lead is not affected by dilute HCl in cold, because," we will analyze the situation step by step.

### Step 1: Understanding the Reaction
Lead (Pb) does not react with dilute hydrochloric acid (HCl) at low temperatures. The general reaction between lead and hydrochloric acid can be represented as:
\[ \text{Pb (s)} + 2 \text{HCl (aq)} \rightarrow \text{PbCl}_2 (s) + \text{H}_2 (g) \]

### Step 2: Formation of Protective Coating
When lead comes into contact with dilute HCl, it can react to form lead(II) chloride (PbCl2). However, this PbCl2 can form a protective coating on the surface of the lead metal. This coating prevents further reaction between lead and the acid.

### Step 3: Analyzing the Options
Now, let's analyze the provided options based on the information we have:

1. **Pb is less electronegative than H**: This statement is true, but it does not explain why lead is not affected by dilute HCl.

2. **PbO film is formed which resists chemical attack by acid**: This is incorrect because there is no formation of PbO in this context.

3. **A protective coating of PbCl2 is formed on Pb surface**: This statement is correct. The formation of PbCl2 creates a barrier that prevents further reaction.

4. **PbO2 film is always present on Pb surface which resists chemical attack**: This is incorrect as well; PbO2 does not play a role in this reaction.

### Step 4: Conclusion
The correct answer is that a protective coating of PbCl2 is formed on the lead surface, which prevents further reaction with dilute HCl.

### Final Answer
Lead is not affected by dilute HCl in cold because a protective coating of PbCl2 is formed on the Pb surface.

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