1. Write the oxidation numbers for each of the following:
Bellwork Wednesday
Write the oxidation numbers for each of the following:
1. K2CrO LiMnO4
3. H2SO SO3
5. Na2SnO KClO3

2. Oxidation is an increase in oxidation number.
Reduction is a decrease in oxidation number.
Oxidizing agent- The substance in a redox reaction that accepts electrons the substance that was reduced *The entire reactant is called the oxidizing agent* Reducing agent- The substance in a redox reaction that donates electrons the substance that was oxidized *The entire reactant is called the reducing agent*

3. 19.3 REDOX Reaction Examples
Identify the element oxidized, the element reduced, the oxidizing agent and the reducing agent for each of the following:
MnO HCl  MnCl2 + Cl2 + 2H2O +4 -2 +1 -1 +2 -1 +1 -2 Mn +4 +2
Gained 2 e-
Reduced
“Oxidizing Agent” (MnO2) Cl -1
Lost 1 e-
Oxidized
“Reducing Agent” (HCl)

4. “Oxidizing Agent” (HNO3)
Identify the element oxidized, the element reduced, the oxidizing agent and the reducing agent for each of the following: Cu + HNO3  Cu(NO3)2 + NO2 + H2O +1 +5 -2 +2 +5 -2 +4 -2 +1 -2 Cu +2
Lost 2 e-
Oxidized
“Reducing Agent” (Cu) N +5 +4
Gained 1 e-
Reduced
“Oxidizing Agent” (HNO3)

5. Let’s Practice! Write the oxidation numbers of the elements and then indicate which substance was oxidized, which was reduced and which are the oxidizing a reducing agents.
2Mg + O2  2MgO AgNO3 + Cu  CuNO3 + Ag Oxidized: Oxidized: Reduced: Reduced: Ox. Agent: Ox. Agent: Red. Agent: Red. Agent: Mg Cu O Ag O2
AgNO3 Mg Cu

6. Let’s Practice! Write the oxidation numbers of the elements and then indicate which substance was oxidized, which was reduced and which are the oxidizing a reducing agents.
CH4 + O2  CO + 2H2O 2Fe2O3 + 3C  4Fe + CO2 Oxidized: Oxidized: Reduced: Reduced: Ox. Agent: Ox. Agent: Red. Agent: Red. Agent: C C O Fe O2
Fe2O3
CH4 C