Watch the demonstrations Write a chemical equation for the reaction State and explain the type of reaction

Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s) Write out half equations for the following reactions Describe each half equation as oxidation or reduction Indicate which species is oxidised and which is reduced Identify the oxidising agent and the reducing agent Ca(s) + I2(s) → CaI2(s) Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)

Rules for assigning oxidation numbers Elements – oxidation number is zero Simple ions - oxidation number is equal to the charge on the ion Compounds – the sum of oxidation numbers equals zero Complex ions - the sum of oxidation numbers is equal to the charge on the ion Usually, in compounds and ions: F -1 Cl -1 Group 1 +1 O -2 Group 2 +2 H +1 Aluminium +3

2H2 (g) + O2 (g) → 2H2O (g) Deduce the oxidation states of each element before and after the reaction Which elements are oxidised and which are reduced?

Oxidation numbers N2 NH3 NO3- State and explain the oxidation number for nitrogen in these substances: N2 NH3 NO3-

combustion of magnesium Identify the element that is oxidised Show that the demonstrations you observed are redox reactions using oxidation numbers: combustion of magnesium displacement reaction between magnesium and copper Identify the element that is reduced Name the oxidising agent and the reducing agent