By carrying electrolysis of which compound , pure hydrogen is obtained

Options

A. Water containing `H_2SO_4`
B. Water containing NaOH
C. `Ba(OH)_2` solution
D. KOH solution

Answer

To determine which compound yields pure hydrogen upon electrolysis, we can follow these steps:

### Step 1: Understand Electrolysis
Electrolysis is a process that uses electricity to drive a chemical reaction, typically to separate elements from their compounds. In this context, we are interested in the electrolysis of a compound that produces pure hydrogen gas.

### Step 2: Identify the Compounds
We need to evaluate the given options (A, B, C, D) to identify which one, when subjected to electrolysis, produces pure hydrogen.

### Step 3: Analyze the Electrolysis of Barium Hydroxide (Ba(OH)₂)
Among the options, we focus on the electrolysis of barium hydroxide solution (Ba(OH)₂).

- When Ba(OH)₂ is electrolyzed, it dissociates into barium ions (Ba²⁺) and hydroxide ions (OH⁻).
- At the cathode (negative electrode), reduction occurs, where hydroxide ions gain electrons to form hydrogen gas (H₂) and water (H₂O):

\[ 2 \text{OH}^- + 2e^- \rightarrow \text{H}_2 + 2 \text{H}_2\text{O} \]

### Step 4: Collecting the Hydrogen Gas
The hydrogen gas produced at the cathode can be collected and is considered pure because it is generated from the reduction of hydroxide ions without any other impurities.

### Step 5: Conclusion
Thus, by carrying out the electrolysis of barium hydroxide (Ba(OH)₂) solution, we can obtain pure hydrogen gas. Therefore, the correct answer is option C.

### Summary of Steps:
1. Understand the electrolysis process.
2. Identify the compounds available for electrolysis.
3. Analyze the electrolysis of barium hydroxide.
4. Collect the hydrogen gas produced.
5. Conclude that option C is correct.