A 0.1250-g sample of octane (C8H18) is burned in a bomb calorimeter with a heat capacity of 5.1 * 102 J/°C. The temperature inside the calorimeter increases by 11.8 °C. What is the ΔE (in kJ/mol octane) for the combustion of octane?

The answer to your question is ΔE = 0.752 kJ/mol

Explanation:

Data

mass of sample = 0.125 g

Heat capacity = 5.1 x 10² J/°C

ΔT = 11.8°C

ΔE = ?

Formula

ΔE = ΔQ + w

We suppose that work W = 0

ΔQ = mCΔT, then

ΔE = mCΔT

Substitution

ΔE = (0.125) (5.1 x 10²) (11.8)

Simplification

ΔE = (63.75) (11.8)

Result

ΔE = 752.25 J/mol or ΔE = 0.752 kJ/mol