Hydrogen can be prepared by

Options

A. Electrolysis of acidified water
B. Bosch's process
C. Lane's process
D. All of these

Answer

To solve the question "Hydrogen can be prepared by," we will analyze each of the provided options step by step.

### Step 1: Electrolysis of Acidified Water
- **Explanation**: When we perform electrolysis on acidified water, an electric current is passed through the water, which has been acidified (usually with sulfuric acid) to enhance conductivity. During this process:
- At the cathode (negative electrode), hydrogen ions (H⁺) gain electrons to form hydrogen gas (H₂).
- At the anode (positive electrode), hydroxide ions (OH⁻) lose electrons to form oxygen gas (O₂).
- **Ratio**: The gases are produced in a 2:1 volume ratio, meaning for every 2 volumes of hydrogen produced, 1 volume of oxygen is produced.
- **Conclusion**: This method can indeed produce hydrogen gas.

### Step 2: Bosch Process
- **Explanation**: The Bosch process is a commercial method for producing hydrogen gas. It involves two main steps:
1. **Coal Gasification**: Coal is reacted with steam at high temperatures (around 1000°C) to produce a mixture known as water gas, which consists of carbon monoxide (CO) and hydrogen (H₂).
2. **Water Gas Shift Reaction**: The water gas is then treated with steam at around 400°C in the presence of catalysts (iron oxide and chromium oxide), resulting in the formation of carbon dioxide (CO₂) and additional hydrogen gas (H₂).
- **Conclusion**: The Bosch process is a valid method for hydrogen production.

### Step 3: Lenz Process
- **Explanation**: The Lenz process involves the oxidation of iron with steam at high temperatures. The reaction can be summarized as follows:
- Iron (Fe) reacts with steam (H₂O) to form iron oxide (Fe₃O₄) and liberates hydrogen gas (H₂).
- **Balanced Reaction**: The balanced equation for this reaction is:
\[ 3Fe + 4H_2O \rightarrow Fe_3O_4 + 4H_2 \]
- **Conclusion**: The Lenz process is also a method for producing hydrogen gas.

### Final Conclusion
- Since hydrogen can be produced by all three methods mentioned (electrolysis of acidified water, Bosch process, and Lenz process), the correct answer to the question is:
**Option 4: All of these.**

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