F5S Chemistry Revision Exercise (Redox Half Equation)

1. Split the following overall ionic equations in two half-equations.

(a) Cl2(aq) + 2Br–(aq) 2Cl–(aq) + Br2(aq)

(b) Cl2(aq) + 2I–(aq) 2Cl–(aq) + I2(aq)

(c) Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s)

(d) MnO4-(aq) + 8H+ + Fe2+(aq) Mn2+(aq) + 4H2O(l) + 5Fe3+(aq)

(e) 2Ag+ (aq) + Cu(s) 2Ag(s) + Cu2+(aq)

(f) Zn(s) + Pb2+(aq) Zn2+(aq) + Pb(s)

2. Both metal displacement and halogen displacement reactions are redox. For the following displacement

reaction, write

(1) complete chemical equations

(2) reduction half equation

(3) oxidation half equation

(4) overall ionic equation

(a) Zinc is added to copper(II) sulphate solution

(b) Chlorine gas mixed with potassium bromide solution.

(c)Bromine liquid is added to potassium iodide solution.

(d) Magnesium is added to lead(II) nitrate solution

3. For the following redox reaction, use the ionic-half equation method to write down their

(1) reduction half equation

(2) oxidation half equation

(3) overall ionic equation (4) any observable change

(a) FeCl2(aq) + 2Cl2(g) FeCl3(aq)

(b) Acidified potassium permanganate solution mixed with iron(II) sulphate solution

(c) Copper is added to concentrated nitric acid

(d) Magnesium is added to dilute nitric acid

(e) Copper is added to concentrated sulphuric acid

(f) Acidified potassium dichromate solution mixed with iron(II) sulphate solution

(g) chemical test of SO2(g)

(h) acidified KMnO4 solution reacts with concentrated hydrochloric acid

4. By use of the ionic half-equation method, give an ionic equation for each of the following reactions.

(a) Cu(s) + NO3-(aq) + H+(aq) gives Cu2+ (aq) + NO (g) + H2O(l)

(b) MnO4-(aq) + I- (aq) + H+ (aq) gives Mn2+(aq) + I2(aq) + H2O(l)

(c) Cr2O72-(aq) + Fe2+(aq) + H+(aq) gives Cr3+(aq) + Fe3+(aq) + H2O(l)