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

Options

A. `4 . 0`
B. `6 . 0`
C. `10 . 22`
D. `20 . 44`

Answer

To solve the problem of how much bromine is required to convert 2 grams of phenol into 2,4,6-tribromophenol, we can follow these steps:

### Step 1: Determine the molecular formula of phenol.
Phenol has the molecular formula \( C_6H_5OH \).

### Step 2: Calculate the molar mass of phenol.
- Carbon (C): 6 atoms × 12 g/mol = 72 g/mol
- Hydrogen (H): 6 atoms × 1 g/mol = 6 g/mol
- Oxygen (O): 1 atom × 16 g/mol = 16 g/mol

Adding these together:
\[ \text{Molar mass of phenol} = 72 + 6 + 16 = 94 \text{ g/mol} \]

### Step 3: Determine the amount of bromine needed for the reaction.
The reaction of phenol with bromine to form 2,4,6-tribromophenol requires 3 moles of bromine for every mole of phenol.

### Step 4: Calculate the molar mass of bromine.
Bromine (Br) has a molar mass of 80 g/mol.

### Step 5: Calculate the amount of bromine required for 94 g of phenol.
Since 1 mole of phenol requires 3 moles of bromine:
\[ \text{Molar mass of bromine needed} = 3 \text{ moles} \times 80 \text{ g/mol} = 240 \text{ g} \]

### Step 6: Set up a proportion to find the amount of bromine needed for 2 g of phenol.
Using the ratio:
\[ \frac{240 \text{ g Br}}{94 \text{ g phenol}} = \frac{x \text{ g Br}}{2 \text{ g phenol}} \]

### Step 7: Solve for \( x \).
Cross-multiplying gives:
\[ x = \frac{240 \text{ g Br} \times 2 \text{ g phenol}}{94 \text{ g phenol}} \]

Calculating this:
\[ x = \frac{480}{94} \approx 5.11 \text{ g Br} \]

### Step 8: Final calculation.
Thus, approximately 5.11 grams of bromine is required to convert 2 grams of phenol into 2,4,6-tribromophenol.