The metal which does not form ammonium nitrate by reaction with dilute nitric acid is

Options

A. Al
B. Fe
C. Pb
D. Mg

Explanation

To determine which metal does not form ammonium nitrate when reacting with dilute nitric acid, we need to analyze the behavior of different metals with nitric acid. Here’s a step-by-step solution:

### Step 1: Understand the Reaction
When metals react with nitric acid (HNO3), they can produce different products depending on the concentration of the acid and the position of the metal in the electrochemical series (ECS).

### Step 2: Identify the Electrochemical Series
The electrochemical series ranks metals based on their reactivity. Metals above lead (Pb) in the series typically react with dilute nitric acid to produce ammonium nitrate (NH4NO3), while metals below lead do not.

### Step 3: Analyze the Reaction Products
1. **For metals above lead**:
- With concentrated HNO3: Nitrogen oxides (e.g., N2O, NO2).
- With dilute HNO3: Ammonium nitrate (NH4NO3) is formed.

2. **For lead and below**:
- With concentrated HNO3: Nitrogen oxides (e.g., N2O).
- With dilute HNO3: Typically, nitrogen oxides like NO are produced, and ammonium nitrate is not formed.

### Step 4: Identify the Metal in Question
From the information above, we can conclude that metals like zinc (Zn), copper (Cu), and magnesium (Mg) will produce ammonium nitrate when reacted with dilute nitric acid. However, lead (Pb) and metals below it in the series will not produce ammonium nitrate.

### Conclusion
The metal that does not form ammonium nitrate by reaction with dilute nitric acid is **Lead (Pb)**.