PowerPoint PresentationIf oxidation occurs, then reduction must
also occur
Any chemical process in which elements undergo a change in
oxidation number is a Redox reaction
Example
This reaction can be thought of as two half reactions
2 Na → 2Na+ + 2e oxidation
Cl2 + 2e → 2Cl- reduction
Identifying Redox
SO3 + H2O → H2SO4
2KNO3 → 2KNO2 + O2
More Definitions
Reducing Agents – elements that undergo oxidation (the cause
reduction in another element)
Oxidizing Agents – undergo reduction
Mg + Cu(NO3) → Cu + Mg(NO3)
Corrosion
When a metal is reduced
When two metals are in contact, the one that is the better reducing
agent (most active) will give up electrons to the other one
The metal that receives the electrons is reduced – called
corrosion