Gas liberated at cathode during Kolbe's electrolysis is

Options

A. Hydrocarbon
B. `CO_(2)`
C. `H_(2)`
D. `N_(2)`

Answer

To determine the gas liberated at the cathode during Kolbe's electrolysis, we can follow these steps:

### Step 1: Understand the Process of Kolbe's Electrolysis
Kolbe's electrolysis involves the electrochemical oxidative decarboxylation of carboxylic acid salts. This process typically occurs with sodium acetate or similar compounds.

**Hint:** Remember that Kolbe's electrolysis is a specific type of electrolysis that involves carboxylic acids.

### Step 2: Identify the Electrolysis Components
In Kolbe's electrolysis, we have two electrodes: the anode and the cathode. At the anode, oxidation occurs, while at the cathode, reduction takes place.

**Hint:** Recall that oxidation involves the loss of electrons, and reduction involves the gain of electrons.

### Step 3: Determine the Reaction at the Cathode
At the cathode, we need to identify which species is undergoing reduction. In the case of sodium acetate electrolysis, water (H2O) is typically present and can participate in the reaction.

**Hint:** Focus on the reactants that are available at the cathode during the electrolysis.

### Step 4: Analyze the Reduction Reaction
The reduction reaction at the cathode can be represented as:
\[ 2H_2O + 2e^- \rightarrow H_2 + 2OH^- \]
This indicates that water is reduced to hydrogen gas (H2) and hydroxide ions (OH^-).

**Hint:** Look for the products formed during the reduction process at the cathode.

### Step 5: Identify the Gas Liberated
From the reduction reaction, we can see that hydrogen gas (H2) is produced at the cathode during Kolbe's electrolysis.

**Hint:** Remember that gases produced during electrolysis are often collected at the electrodes.

### Conclusion
Thus, the gas liberated at the cathode during Kolbe's electrolysis is hydrogen gas (H2).

**Final Answer:** Hydrogen gas (H2) is liberated at the cathode during Kolbe's electrolysis.

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