C4 - The characteristic properties between acids and bases

1 Describe neutrality and relative acidity and alkalinity in terms of pH (whole numbers only) measured using full-range indicator and litmus.

All substances are divided into three categories:

How can this be measured?

We usually do this by measuring the pH of the substance. 

What is the pH?

Simply a measure of the Hydrogen ion concentration in a substance.

We measure pH using the pH scale.

• pH 1-6 substances are usually acidic
• pH 7 substances are usually neutral
• pH 7-14 substances are usually alkaline

Universal Indicator This is a substance that changes color when it is added to another substance. What color it changes to depends on the pH of the substance. Above: A diagram of a universal indicator

Litmus Paper

This is an indicator also used to test for acidity, neutrality or alkalinity in a substance. We use something called litmus paper to test for this. If we want to test for…