The current needed to reduce 26.6 g of nitrobenzene to aniline in acidic medium, is

Options

A. 0.4 F
B. 0.6 F
C. 0.8 F
D. 1.2 F

Answer

To determine the current needed to reduce 26.6 g of nitrobenzene (C6H5NO2) to aniline (C6H5NH2) in acidic medium, we can follow these steps:

### Step 1: Write the balanced chemical equation
The reduction of nitrobenzene to aniline can be represented by the following balanced equation:
\[ \text{C}_6\text{H}_5\text{NO}_2 + 6\text{H}^+ + 6e^- \rightarrow \text{C}_6\text{H}_5\text{NH}_2 + 2\text{H}_2\text{O} \]

### Step 2: Calculate the molar mass of nitrobenzene
The molar mass of nitrobenzene (C6H5NO2) can be calculated as follows:
- Carbon (C): 12.01 g/mol × 6 = 72.06 g/mol
- Hydrogen (H): 1.008 g/mol × 5 = 5.04 g/mol
- Nitrogen (N): 14.01 g/mol × 1 = 14.01 g/mol
- Oxygen (O): 16.00 g/mol × 2 = 32.00 g/mol

Adding these together:
\[ 72.06 + 5.04 + 14.01 + 32.00 = 123.07 \text{ g/mol} \]
So, the molar mass of nitrobenzene is approximately 123 g/mol.

### Step 3: Determine the number of moles of nitrobenzene
To find the number of moles of nitrobenzene in 26.6 g, we use the formula:
\[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} \]
\[ \text{Number of moles} = \frac{26.6 \text{ g}}{123 \text{ g/mol}} \approx 0.216 \text{ moles} \]

### Step 4: Calculate the number of electrons required
From the balanced equation, we see that 1 mole of nitrobenzene requires 6 moles of electrons for reduction. Therefore, for 0.216 moles of nitrobenzene:
\[ \text{Electrons required} = 0.216 \text{ moles} \times 6 \text{ moles of e}^- = 1.296 \text{ moles of e}^- \]

### Step 5: Convert moles of electrons to charge
Using Faraday's constant (approximately 96500 C/mol), we can convert moles of electrons to charge:
\[ \text{Charge (Q)} = \text{Number of moles of e}^- \times \text{Faraday's constant} \]
\[ Q = 1.296 \text{ moles} \times 96500 \text{ C/mol} \approx 124,000 \text{ C} \]

### Step 6: Calculate the current
If we assume the time (t) for the reduction process is 1 hour (3600 seconds), we can calculate the current (I) using the formula:
\[ I = \frac{Q}{t} \]
\[ I = \frac{124,000 \text{ C}}{3600 \text{ s}} \approx 34.44 \text{ A} \]

### Final Answer
The current needed to reduce 26.6 g of nitrobenzene to aniline in acidic medium is approximately **34.44 A**.

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