Candle Practical Report
Rebekah Flood
Introduction
The aim of the experiment is to determine how the temperature of the candle’s surrounding area
affects the time taken for the flame to extinguish.
A chemical reaction is the formation of a new substance. Combustion is a chemical reaction
because it produces a new substance. This is evident as colour, odour, heat and light are
produced. Oxygen and fuel are required for a flame to burn. A candle burns through using liquid
wax as a fuel which has been melted by the flame, then drawn up the wick. This wax is then
vaporised and broken down into hydrogen and carbon molecules (National Candle Association,
2017). These molecules move up the flame and react with oxygen to form water vapour (H2O) and
carbon dioxide (CO2), as well as converting light and heat energy (National Candle Association,
2017). The flame extinguishes when the oxygen level depletes.
In most chemical reactions, with increased temperature comes increased rate of reaction. This
applies to the rate at which the oxygen reacts with the fuel. Therefore, when the oxygen is limited
and temperature increased, the fire extinguishes faster. The opposite applies when the
temperature cools (sciencing.com, 2017).
Combustion - the process of burning something (Dictionary.com, 2017).
Chemical Reactions - A change that produces a new substance.
Vaporise - convert or be converted into vapour (Dictionary.com, 2017).
The effect of differing temperatures on the time taken for the flame of a candle to extinguish will
be tested. This will be carried out by placing the candle in an area with a specific temperature,
lighting the wick and then covering the candle with a beaker and recording the time taken for the
flame to extinguish.
Aim
The aim is to determine the effect of differing temperatures on the time taken for the flame of a
candle to extinguish.
Hypothesis
The hypothesis is that as the temperature increases, the time taken for the flame to extinguish will
shorten.
Hypothesis Explanation
This is because as the temperature increases, the rate of oxygen conversion increases, causing a
depletion of oxygen to occur faster. Once the oxygen is converted, the flame extinguished as it
cannot burn without oxygen (National Candle Association, 2017).
Variables
Independent Variable - the independent variable is the temperature of the candle’s surrounding
area. Temperatures of 0°, 10°, 20° and 50° Celsius were used to vary the dependant variable.
Dependant Variable - the dependant variable is the time taken for the candle to extinguish which
will be measured using an iPad.
Controlled Variables
Apparatus
1. Freezer: 0°C
2. Fridge: 10°C
3. Room temperature: 20°C
4. Oven: 50°C
5. Oven gloves
Controlled Variables How they were controlled Why they were controlled
Candle wick width Identical candles were used
which ensured the wick was also
identical.
So as not to vary the effect of the
independent variable.
Type of candle Identical candles were used. This prevented differ...
