- The pH scale is a numerical scale which is used to show how acidic or alkaline a solution is.
- It goes from 1 – 14 (extremely acidic substances can have values of below 1).
- All acids have pH values below 7, all alkalis have pH values of above 7.
- The lower the pH then the more acidic the solution is.
- The higher the pH then the more alkaline the solution is.
- A solution of pH 7 is described as being neutral e.g. water.
The pH scale showing acidity, neutrality and alkalinity
- Universal indicator is a mixture of different indicators which is used to measure the pH.
- A drop is added to the solution and the colour is matched with a colour chart which indicates the pH which matches specific colours.
The pH scale with the Universal Indicator colours which can be used to determine the pH of a solution