1. Acids, Alkalis & Salts GCSE REVISION

2. 1. Name three indictors  Methyl Orange  Phenolphthalein  Universal Indictor  Litmus (any three)

3. 2. Explain why Universal indicator is the best indicator.  Because it gives an indication of strong and weak in addition to whether a substance is an acid, an alkali or neutral.

4. 3. Give the colours and pH scale for universal indicator.  1-2: Red  3-4: Orange  5-6: Yellow  7: Green  8-10:Blue  11-12: Indigo  13-14: Violet

5. 4.What are the products of a neutralisation reaction?  Salt and water

6. 5. Write a word/balanced chemical equation for the reaction between sodium hydroxide and hydrochloric acid Sodium hydroxide + Hydrochloric Acid Sodium Chloride + water NaOH + HClNaCl + H 2 O

7. 6. Write a word/balanced chemical equation for the reaction between aluminium oxide and sulphuric acid Aluminium oxide + Sulphuric Acid Aluminium sulphate + water Al 2 O 3 + 3H 2 SO 4 Al 2 (SO 4 ) 3 + 3H 2 O

8. 7. a. Draw the apparatus you would use to collect the gas when zinc reacts with sulphuric acid. b. Name the gas produced and give the test  b. Hydrogen gas.  A lit splint goes out with a squeaky pop. a.

9. 8. Explain how you would prepare copper sulphate in a lab using copper carbonate and sulphuric acid.

10. 9. a)Explain why you cannot use filtration-evaporation to prepare sodium chloride in a lab. b) Give an alternative method that you could use  a) Sodium carbonate is not insoluble. Therefore you cannot filter off the excess before evaporation.  b) Titration using sodium hydroxide and hydrochloric acid.

11. 10. Name the reaction that is used to prepare insoluble salts.  Precipitation

12. The following questions are Higher Tier only

13. 11. a) What is meant by a strong acid? b) Give an example  a) One which dissociates (breaks up) fully into ions when aqueous  b) HCl (aq) H 2 SO 4 (aq)

14. 12. Why is the pH of weak acids higher than that of the same volume of strong acids?  Because weak acids do not dissociate fully when aqueous.  This means that there are less H+ ions present in the solution, leading to a higher pH.