Review all

        Target revision in:
1 Draw an oxide ion (3)      Nucleus with 8p and 8n = 1

electron shells = 1

Brackets and 2- = 1

Drawing atoms and ions
2 What does 37Cl and 35Cl have in common?  (2)  17 protons (1) and 17 electrons (1) Isotopes and the definition
3 How does 37Cl and 35Cl differ? (1)  20 Neutrons and 18 neutrons (1) Isotopes and the definition
4 Write a balanced chemical reaction for Aluminium and Sulphuric acid (4) Formula, acid reactions and balancing
  2Al      +      3H2SO4      à         Al2(SO4)3          +            3H2
  H2SO4 = 1           Al2(SO4)3 = 1                   H2 = 1                 Balanced = 1
5 Assign Oxidation numbers to determine what has been reduced in the reaction above, explain your answer  (6)  
  2Al      +      3H2SO4      à         Al2(SO4)3          +            3H2          Ox no's and REDOX
  Al = 0           H = 1+ S = 6+  O = 2-         Al = 3+ S = 6+  O = 2-                H = 0   1 mark for each element correct on both sides of the arrow

Hydrogen has been reduced as its Ox No has reduced / gained electrons
6 What is the reducing agent? (1)  Al Ox and Red agents
7 How would you define reduction (1)  gain of electrons OIL RIG
8 Calculate the % of S in H2SO4 (2)  (32.1/98.1) x 100 (1)  = 32.7 (3sf) (1) % element in a molecule
9 Sulphuric acid is a strong acid, explain what this means?  (1)  Dissociates completely Acids definitions
10 Sulphuric acid contains 2 protons, what do we call acids that contain 2 protons  (1)  Diprotic acids
11 Sulphuric acid can be neutralised by alkalis, what is an alkali?  (1) a species when dissolved in water releases hydroxide ions, OH 1- Alkali definition
12 Look at this reaction:   
  Br2 + H2S à 2HBr + S
  Br = 0   H = 1+ S = 2-   H = 1+ Br = 1-   0
a Assign oxidation numbers to each element  (3)  1 mark for each element correct on both sides of the arrow
b What is the spectator ion ? Explain your answer (2)  H+ (1) as there is no change in the Ox No Ox no's and spectator ions
c Rewrite the reaction as an ionic equation  (2)   S2-  = 1    and 2Br 1-  = 1 ionic equations
  Br2 + S2- à 2Br 1- + S