A quantity of electrcity required to reduce `12.3` g of nitrobenzene to aniline arising `50%` current efficiency is

Options

A. 115800C
B. 579000C
C. 231600C
D. 289500C

Answer

To solve the problem of calculating the quantity of electricity required to reduce 12.3 g of nitrobenzene to aniline with a current efficiency of 50%, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Chemical Reaction**:
The reduction of nitrobenzene (C₆H₅NO₂) to aniline (C₆H₅NH₂) involves the transfer of electrons. The overall reaction can be represented as:
\[ \text{C}_6\text{H}_5\text{NO}_2 + 6e^- + 6\text{H}^+ \rightarrow \text{C}_6\text{H}_5\text{NH}_2 + 2\text{H}_2\text{O} \]
This indicates that 6 electrons are required for the reduction of one mole of nitrobenzene to aniline.

2. **Calculate the Molar Mass of Nitrobenzene**:
The molar mass of nitrobenzene (C₆H₅NO₂) can be calculated as follows:
- Carbon (C): 12 g/mol × 6 = 72 g/mol
- Hydrogen (H): 1 g/mol × 5 = 5 g/mol
- Nitrogen (N): 14 g/mol × 1 = 14 g/mol
- Oxygen (O): 16 g/mol × 2 = 32 g/mol
\[ \text{Total Molar Mass} = 72 + 5 + 14 + 32 = 123 \text{ g/mol} \]

3. **Calculate the Number of Moles of Nitrobenzene**:
Using the given mass of nitrobenzene (12.3 g), we can calculate the number of moles:
\[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} = \frac{12.3 \text{ g}}{123 \text{ g/mol}} = 0.1 \text{ mol} \]

4. **Determine the Total Number of Electrons Required**:
Since 6 electrons are required to reduce 1 mole of nitrobenzene, for 0.1 moles:
\[ \text{Total electrons} = 0.1 \text{ mol} \times 6 \text{ e}^- = 0.6 \text{ mol of e}^- \]

5. **Convert Moles of Electrons to Charge (Coulombs)**:
Using Faraday's constant (approximately 96500 C/mol), we can find the total charge:
\[ Q = \text{moles of e}^- \times \text{Faraday's constant} = 0.6 \text{ mol} \times 96500 \text{ C/mol} = 57900 \text{ C} \]

6. **Adjust for Current Efficiency**:
Since the current efficiency is 50%, we need to divide the charge by the efficiency:
\[ Q_{\text{actual}} = \frac{57900 \text{ C}}{0.5} = 115800 \text{ C} \]

### Final Answer:
The quantity of electricity required to reduce 12.3 g of nitrobenzene to aniline at 50% current efficiency is **115800 Coulombs**.

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