Combustion and Thermal Decomposition
This page delves into two important types of chemical reactions: combustion and thermal decomposition, providing crucial Chemical reactions KS3 Worksheet content.
Combustion is the burning of a fuel in oxygen. A fuel is a substance that stores energy in a chemical form.
Definition: Combustion is a chemical reaction where a fuel burns in the presence of oxygen, releasing energy in the form of heat and light.
When a carbon-based fuel undergoes combustion, it produces water and carbon dioxide.
Example: The combustion equation for methane is:
methane + oxygen β carbon dioxide + water
Hydrogen can be used as an alternative fuel, which is more environmentally friendly as it doesn't produce carbon dioxide.
Highlight: The combustion of hydrogen only produces water: hydrogen + oxygen β water
Thermal decomposition is a reaction where substances are broken down using heat.
Definition: Thermal decomposition is a chemical reaction where a compound breaks down into simpler substances when heated.
An example of thermal decomposition is the breakdown of metal carbonates:
Example: zinc carbonate β zinc oxide + carbon dioxide
This reaction can be tested by bubbling the produced gas through limewater. If the limewater turns cloudy, it confirms the presence of carbon dioxide.
Vocabulary: Limewater is a solution of calcium hydroxide used to test for the presence of carbon dioxide.
This page provides essential information for understanding combustion and chemical reactions combined science gcse topics, as well as thermal decomposition reaction examples for students.
