Introduction

Energy content is an important property of fuels. This property helps scientists and engineers determine the usefulness of a fuel. Energy content is the amount of heat produced by the burning of 1 gram of a substance, and is measured in joules per gram (J/g).

You can determine energy content of a fuel by burning an amount of the fuel and capturing the heat released in a known mass of water in a calorimeter. If you measure the initial and final temperatures, the energy released can be calculated using the equation

where H = heat energy absorbed (in J), Δt = change in temperature (in °C), m = mass (in g), and Cp = specific heat capacity (4.18 J/g°C for water). Dividing the resulting energy value by grams of food burned gives the energy content (in J/g).

Objectives