1. The following slides should help you with your revision, but should not be your only form of revision.
Remember to use your notes, a textbook, websites and Past Papers to help you. You can also ask a chemistry teacher for help too.

2. A measure of hydrogen ion concentration
What is pH?
A measure of hydrogen ion concentration

3. A higher concentration of H+ gives what type of solution?
Acid

4. A higher concentration of OH- gives what type of solution?
Alkali

5. Why does water only very slightly conduct electricity?
Water molecules contain very few ions, mainly it exists as molecules.
H2O (l) H+ (aq) + OH- (aq) .

6. In an acidic solution, describe [H+] and the [OH- ].
In an acidic solution the concentration of hydrogen ions is greater than the concentration of hydroxide ions.

7. In an alkaline solution, describe [H+] and the [OH- ].
In an alkaline solution the concentration of hydroxide ions is greater than the concentration of hydrogen ions.

8. In neutral solution, describe [H+] and the [OH- ].
In a neutral solution, the concentration of hydrogen ions is equal to the concentration of hydroxide ions..

9. Describe the effect of diluting an acid in terms of acidity and pH.
Diluting an acid by a factor of 10 (making 1cm3 up to 10 cm3) makes the pH higher by 1 and the solution less acidic.
This is because the concentration of hydrogen ions is smaller.

10. Describe the effect of diluting an acid in terms of alkalinity and pH.
Diluting an alkali by a factor of 10 makes the pH lower by 1 and the solution less alkaline.
This is because the concentration of hydroxide ions is smaller.

11. What happens to the pH of an alkali if an acid is added to it?
pH falls towards 7

12. What happens to the pH of an acid if an alkali is added to it?
pH rises towards 7.

13. What is produced if an acid neutralises an alkali?
Salt & Water.

14. What is produced if an alkali neutralises an acid?
Salt & Water.

15. What is a salt?
A SALT is a substance in which the hydrogen ion of an acid has been replaced by a metal ion or the ammonium ion.

16. How does a salt get its name?
The first part of the name of a salt comes from the metal in the acid ‘neutraliser’ and the ending comes from the acid. Eg
potassium + sulphuric potassium + water
hydroxide acid sulphate

17. Give the ‘Surname’ of the following Salts
ACID
SALT
HYDROCHLORIC ACID
CHLORIDE
SULPHURIC ACID
SULPHATE
NITRIC ACID
NITRATE
PHOSPHORIC ACID
PHOSPHATE

18. Complete the word equations:
potassium nitric potassium water
hydroxide acid nitrate
hydrochloric + sodium sodium water
acid hydroxide chloride