4.4.2.4

4.4.2.4 The pH scale and neutralisation

Content

  • Acids produce hydrogen ions (H+) in aqueous solutions. AT 3

GCSE Chemistry (8462). For exams 2018 onwards. Version 1.0

Content

Key opportunities for skills development

Content

Key opportunities for skills development

Aqueous solutions of alkalis contain hydroxide ions (OH).

This is an opportunity to

investigate pH changes The pH scale, from 0 to 14, is a measure of the acidity or alkalinity when a strong acid

of a solution, and can be measured using universal indicator or a pH neutralises a strong alkali.probe.

A solution with pH 7 is neutral. Aqueous solutions of acids have pH values of less than 7 and aqueous solutions of alkalis have pH values greater than 7.

In neutralisation reactions between an acid and an alkali, hydrogen ions react with hydroxide ions to produce water.

This reaction can be represented by the equation:

  • Students should be able to:
  • describe the use of universal indicator or a wide range indicator to measure the approximate pH of a solution
  • use the pH scale to identify acidic or alkaline solutions.



AT 3 Use of appropriate apparatus and techniques for conducting and monitoring chemical reactions, including appropriate reagents and/or techniques for the measurement of pH in different situations (links to A-level AT a and d).