CE/KS3 Chemistry: Acids, Alkalis and Indicators

Common Entrance / KS3 Chemistry – Acids, Alkalis and Indicators

✅  Learn or revise complicated concepts easily
✅  Information broken down into short chunks
✅  Full-colour illustrations on every page

Topics Covered Include:

• Glossary of key terms
• Understanding the pH scale
• Identifying acids and alkalis using indicators
• Litmus
• Red cabbage indicator
• The pH of everyday substances
• Weak and Strong Acids and Alkalis
• Hazard Symbols and their meanings
• Working Safely and handling chemicals
• Indicators
• Neutralisation

What are Acids, Alkalis and Indicators?

Acids are substances that release hydrogen ions when dissolved in water. Common examples of acids include lemon juice, vinegar and various acids.

Alkalis, sometimes referred to as bases, release hydroxide ions when dissolved in water. Common examples of alkalis include baking soda and lye.

An indicator is a substance that changes colour in the presence of an acid or an alkali. Indicators can be used to determine the pH of a solution, which is a measure of its acidity or basicity. Examples of indicators include litmus paper, red cabbage juice, and phenolphthalein.

The pH scale ranges from 0 to 14, with 0 being the most acidic and 14 being the most alkaline. A pH of 7 is neutral, meaning it is neither acidic nor alkaline. A pH less than 7 is acidic, and a pH greater than 7 is alkaline. Indicators are used to determine the pH of a solution by observing the colour change of the indicator in the solution.

Understanding the properties of acids and alkalis and how to use indicators to determine pH, is essential in many fields, such as chemistry, biology, and medicine. It is also very important in the lab or field of research, as well as in industry and everyday life, in order to ensure safety and the correct use of chemicals.

Indicators

Substances that change colour when exposed to acids and alkalis are called indicators. Two common examples are litmus and red cabbage.

Litmus is a natural pH indicator made from lichens. It turns red in acidic solutions and blue in basic solutions.

Red cabbage indicator is a pH indicator made, as the name suggests, from red cabbage. It changes colour depending on the pH of the solution it is added to. Red cabbage indicators are red in acidic solutions, purple in neutral solutions, and blue in alkali solutions.

Our acids and alkalis KS3 learning materials cover all topics in detail with easy-to-digest information and plenty of visual learning aids.

Engaging, full-colour illustrations on every page

Text broken down into bite-sized chunks on a lightly shaded background

A simple, easy-to-understand glossary of key terms