What amount of bromine will be required to convert 4 g of phenol into 2, 4, 6-tribromophenol?

Options

A. `4.00`
B. `6.00`
C. `10.22`
D. `20.44`

Answer

To determine the amount of bromine required to convert 4 g of phenol into 2,4,6-tribromophenol, we can follow these steps:

### Step 1: Write the Reaction
The reaction of phenol with bromine can be represented as:
\[ \text{C}_6\text{H}_5\text{OH} + 3\text{Br}_2 \rightarrow \text{C}_6\text{H}_2\text{Br}_3\text{OH} + 3\text{HBr} \]
This shows that one molecule of phenol reacts with three molecules of bromine to produce 2,4,6-tribromophenol.

### Step 2: Calculate the Molar Mass of Phenol
The molecular formula of phenol is \( \text{C}_6\text{H}_5\text{OH} \).
- Carbon (C): 12 g/mol × 6 = 72 g/mol
- Hydrogen (H): 1 g/mol × 6 = 6 g/mol
- Oxygen (O): 16 g/mol × 1 = 16 g/mol

Total molar mass of phenol:
\[ 72 + 6 + 16 = 94 \text{ g/mol} \]

### Step 3: Calculate the Moles of Phenol
To find the number of moles of phenol in 4 g:
\[ \text{Moles of phenol} = \frac{\text{mass}}{\text{molar mass}} = \frac{4 \text{ g}}{94 \text{ g/mol}} \approx 0.04255 \text{ mol} \]

### Step 4: Determine Moles of Bromine Required
From the balanced equation, we see that 1 mole of phenol requires 3 moles of bromine. Therefore, the moles of bromine required for 0.04255 moles of phenol is:
\[ \text{Moles of bromine} = 3 \times 0.04255 \text{ mol} \approx 0.12765 \text{ mol} \]

### Step 5: Calculate the Mass of Bromine Required
The molar mass of bromine (Br) is approximately 80 g/mol. Therefore, the mass of bromine required is:
\[ \text{Mass of bromine} = \text{moles} \times \text{molar mass} = 0.12765 \text{ mol} \times 80 \text{ g/mol} \approx 10.21 \text{ g} \]

### Final Answer
The amount of bromine required to convert 4 g of phenol into 2,4,6-tribromophenol is approximately **10.21 g**.

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