The pH scale shows how acidic a substance is. Learn what pH means and how it is measured in this KS3 chemistry guide from BBC Bitesize. Neutralisation reactions Acids and alkalis react together in ...

In chemistry this is done according ... it is not possible to know what the colour means. If universal indicator was used then the pH would be 7 (neutral). Universal indicator is supplied as ...

Soil pH or soil reaction is an indication of the acidity or alkalinity of soil and is measured in pH units. Soil pH is defined as the negative logarithm of the hydrogen ion concentration. The pH scale ...