Which of the following metals does not liberate hydrogen from acids?

Options

A. Fe
B. Cu
C. Mg
D. Zn

Explanation

To determine which metal does not liberate hydrogen from acids, we need to analyze the reactivity of the given metals in relation to hydrogen. Here’s a step-by-step solution:

### Step 1: Understand the concept of reactivity
Metals can react with acids to liberate hydrogen gas. The ability of a metal to displace hydrogen from an acid depends on its reactivity. Metals that are more reactive than hydrogen can displace hydrogen ions from acids, while those that are less reactive cannot.

### Step 2: Identify the metals in the options
The metals mentioned in the question are:
- Fe (Iron)
- Cu (Copper)
- Mg (Magnesium)
- Zn (Zinc)

### Step 3: Analyze the reactivity of each metal
1. **Fe (Iron)**: Iron is more reactive than hydrogen and can displace hydrogen from acids, thus liberating hydrogen gas.
2. **Cu (Copper)**: Copper is less reactive than hydrogen and does not displace hydrogen from acids, meaning it does not liberate hydrogen.
3. **Mg (Magnesium)**: Magnesium is more reactive than hydrogen and can liberate hydrogen from acids.
4. **Zn (Zinc)**: Zinc is also more reactive than hydrogen and can liberate hydrogen from acids.

### Step 4: Conclusion
From the analysis, the only metal that does not liberate hydrogen from acids is **Cu (Copper)**.

### Final Answer
**Cu (Copper)** does not liberate hydrogen from acids.

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