In a combustion reaction, fuel is burned and reacts with oxygen to release energy.

In a fair test, variables are controlled so that only one change affects the dependent variable.

Control variables are all variables, other than the independent and dependent variables, that are kept constant/the same in an investigation.

A fuel is a substance that releases its stored energy when it undergoes combustion.

Comparing fuels

Science

Heating and cooling

Cooling curve: practical

Exothermic and endothermic chemical reactions

Power stations

Using renewable energy resources

In the Carbon Cycle and Climate Change unit, pupils will build on their understanding of fuels and energetics to learn about the carbon cycle and the impact of human activity on climate.

In the Understanding chemical reactions unit, pupils learnt about how atoms move around to form new substances in chemical reactions and about some common types of chemical reactions.

This unit examines energy changes in state, exothermic and endothermic reactions, and energy transfers in various processes. It emphasises objectivity, accuracy, and precision in scientific enquiries, data interpretation, and the use of tables, graphs, and reliable methods.

Fuels and energetics

Physical activity and equipment requiring safe use

The process of dissolving a substance in water.

A chemical reaction in which a compound reacts with oxygen.

The process of a liquid turning into a gas.

Whenever energy is released in a chemical reaction. 

Which one of the following is a correct statement about combustion?

If the independent variable is the type of fuel, what would the dependent variable be in an experiment comparing energy transfer?

A {{}} is a substance that releases its stored energy when it undergoes combustion. It's crucial for the process of energy transfer by heating.

To ensure the experiment takes the same amount of time for each fuel.

To make sure the experiment is fair by only changing the type of fuel.

To prevent any accidents during the experiment.

Why is it important to use the same mass of fuel for each measurement when comparing the energy released by burning different fuels?

Record the mass of each fuel (should be the same).

Record the starting temperature of the water.

Heat water in a boiling tube by burning the fuel.

Measure the temperature increase of the water.

Order the following steps to correctly set up an experiment comparing the energy transferred by different fuels, starting with recording the starting mass of each fuel.

They are the different types of fuels being tested.

They are the outcomes measured in the experiment.

They ensure the test remains fair by keeping certain conditions the same.

They are changed to observe different results.

What role do control variables play in an experiment comparing the energy transferred by burning different fuels?

What is a sign that a chemical reaction is endothermic?

To ensure that the experiment is more complex.

To make sure the experiment is quickly completed.

To identify which variable is responsible for the observed changes.

Why is it important to only change one independent variable at a time in an experiment?

To ensure the results are reliable and not due to chance.

To see if the experiment gives different results each time.

Because it is always required in scientific research.

What is the main reason for repeating an experiment several times?

In an experiment to determine how temperature affects the solubility of a salt in water, what is the dependent variable?

Hydrochloric acid and magnesium react to produce hydrogen gas. Identify the variable for an investigation to see how the mass of magnesium affects the volume of gas produced.

A {{}} variable is any variable that is kept constant throughout the experiment to ensure that the test results are due solely to the change in the independent variable.

Starter Quiz

What is a sign that a chemical reaction is endothermic?