1. Acids and Bases

2. How acidic a substance is, or how basic a substance is, is measured on a scale known as the pH scale. This is a logarithmic scale that goes from 1 to 14

3. LecturePLUS Timberlake3 pH Range 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Neutral [H + ] > [OH - ] [H + ] = [OH - ] [OH - ] > [H + ] Acidic Basic

4. We can find out if a substance is an acid or a base or neutral by using indicators. Litmus paper is an indicator. Red litmus turns blue in a base Blue litmus turns red in an acid. If both red and blue litmus paper do not change, then the substance is neutral.

5. Neutral 7 on the pH scale is neutral. It is neither an acid nor a base. Pure water is neutral.

7. LecturePLUS Timberlake7 pH of Some Common Acids gastric juice1.0 lemon juice2.3 vinegar2.8 orange juice3.5 coffee5.0 milk6.6

8. LecturePLUS Timberlake8 pH of Some Common Bases blood 7.4 tears 7.4 seawater 8.4 milk of magnesia10.6 household ammonia11.0

9. Universal pH paper This is used to tell more precisely the pH of a substance.

10. Universal pH paper pH23456789101112 Colo ur yyyyggg/bbvvv purpleblueorangered To tell the pH more precisely you dip the universal pH paper into a solution and it changes colour, you then can match the colour to the colour chart provided to decide what number(s) the pH is. Here I dipped the pH paper into a solution and it turned orange. Is the substance an acid or a base?

11. Universal pH paper pH23456789101112 Col our yyyyggg/bbvvv purpleblueorangered If you dip the universal pH paper into a solution and it changes colour, you then can match the colour to the colour chart provided to decide what the pH is. Here I dipped the pH paper into a solution and it turned orange. Is the substance an acid or a base? A BASE, because any number higher than 7 is a base.

12. Can you tell what the nature of substance on A and B are? This is red litmus with a drop of a liquid here T his is blue litmus with a drop of a liquid here A B

13. Can you tell what the nature of substance on A and B are? This is red litmus with a drop of a liquid here T his is blue litmus with a drop of a liquid here A B A BASE AN ACID