1. Chemical formulae of ionic compounds:
iron (III) chloride FeCl3
nickel (II) oxide NiO
chromium (VI) oxide CrO3
silver (II) chloride AgCl2
vanadium (II) bromide VBr2
zinc (I) sulphate Zn2SO4
iron (III) hydroxide Fe(OH)3
manganese (II) oxide MnO
manganese (III) oxide Mn2O3
copper (II) sulphate CuSO4
mercury (II) chloride HgCl2

2. 2. Write a formula for the following pairs of ions and then write a name for them. Remember, only compounds of transition metals need the Roman numerals. The first one is done for you.
Cu2+ and Cl- CuCl2 copper (II) chloride
Ti2+ and O2- TiO titanium (II) oxide
Ca2+ and S2- CaS calcium sulphate
Na ion and N3- Na3N sodium nitride
Mg ion and OH- Mg(OH)2 magnesium hydroxide
Zn2+ and (NO3-) Zn(NO3)2 zinc (II) nitrate
K+ and F- KF potassium fluoride

3. 3. a) magnesium (Mg2+) and chloride (Cl-) ions b) Magnesium is in group 2 and always has a valency of 2. c) It is too reactive and bonded too strongly to the chlorine. d) On following slide

4. Electrolyte (magnesium chloride solution)
negative electrode
positive electrode
Mg2+ + 2e- → Mg
2Cl- → Cl2 + 2e-
Cl-
Electrolyte (magnesium chloride solution)
Mg2+
Cl-
Mg2+