Activity Series ● Used to determine the products of a single replacement reaction – An element higher in the series will replace a lower element in a compound ● Zn(s) + CuCl 2 (aq) → ZnCl 2 (aq) + Cu ● Determine what is oxidized and what is reduced ● What conclusion can you make about oxidation and replacement?

Writing Half Reactions ● CH 4 + 2O 2 → CO 2 + 2H 2 O ● oxidation: CH 4 → CO 2 ● reduction: 2O 2 → 2H 2 O ● Zn + 2HCl → ZnCl 2 + H 2 ● ox: Zn → Zn e - ● red: 2e - + 2H + → H 2 ● overall: Zn + 2H + → Zn +2 + H 2

Balancing Redox by Half Reaction Method ● 1. write half reaction for oxidation reduction – Do not include polyatomic ions that do not change ● 2. For each half reaction: – Balance all elements except H and O – Balance O by adding H 2 O – Balance H by adding H+ – Balance charge using electrons ● 3 if necessary, multiply one or both of the balanced half reactions to equalize the number of electrons in the 2 half reactions ● 4. add half reactions – cancel identical species on opposite sides of the arrow ● 5. check elements and charges are balanced