The heat liberated on complete combustion of `7.8g` benzene is `327kJ`. This heat has been measured at constant volume and at `27^(@)C`. Calculate heat of combustion of benzene at constant pressure at `27^(@)C`. `(R=8.3 J mol^(-1)K^(-1))`

Options

A. `-3274 kJ`
B. `-1312 kJ`
C. `-4442 kJ`
D. `-1981 kJ`

Explanation

To solve the problem of calculating the heat of combustion of benzene at constant pressure, we will follow these steps:

### Step 1: Identify the given data
- Heat liberated on complete combustion of benzene: \( q = 327 \, \text{kJ} \)
- Mass of benzene: \( m = 7.8 \, \text{g} \)
- Molar mass of benzene (\( C_6H_6 \)):
\[
M = 12 \times 6 + 1 \times 6 = 78 \, \text{g/mol}
...