Question

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?

Answer 1

Answer:

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