If universal indicator is added to a solution it changes to a colour that shows the pH of the solution. Universal indicator is a mixture of a variety of other indicators and can be used to measure ...

In the middle, neutral pH 7 is indicated by green. When using universal indicator paper, we get more accurate results by putting only a small spot of the test solution on the paper, and then ...

The yellow scale on the left shows the amount of chlorine in the water. This test for chlorine is not a pH test but the reddish color on the right is a pH indicator, which shows the how acidic or ...