In which from zinc metal is used in laboratory to prepare hydrogen ?

Options

A. Rod
B. powder
C. Filling
D. Granules

Answer

To determine in which form zinc metal is used in the laboratory to prepare hydrogen, we can follow these steps:

### Step 1: Understand the Question
The question asks for the specific form of zinc that is utilized in laboratory settings to generate hydrogen gas.

**Hint:** Identify the different physical forms of zinc that can be used in reactions.

### Step 2: Identify Common Forms of Zinc
Zinc can be found in various forms such as:
- Rods
- Powder
- Granules
- Swelling (which is not a standard form)

**Hint:** Consider the properties of each form and how they might affect chemical reactions.

### Step 3: Analyze the Properties of Each Form
- **Zinc Rods:** These are solid and may not have a high surface area for reactions.
- **Zinc Powder:** While it has a larger surface area than rods, it can be difficult to handle and may react too quickly.
- **Zinc Granules:** These are small, irregular pieces of zinc that have a good balance of surface area and ease of handling. They are also porous.
- **Zinc Swelling:** This is not a recognized form of zinc.

**Hint:** Think about how the surface area and reactivity of zinc affect the production of hydrogen.

### Step 4: Determine the Best Form for Hydrogen Production
Granulated zinc is preferred in laboratory settings because:
- It is highly porous, which increases the rate of reaction.
- It often contains impurities (like copper) that can act as catalysts, further speeding up the reaction.

**Hint:** Consider why the physical characteristics of granulated zinc make it suitable for producing hydrogen.

### Step 5: Conclusion
Based on the analysis, the correct form of zinc used in laboratories to prepare hydrogen is **granulated zinc**.

**Final Answer:** The correct answer is **granules** (option 4).