9.2 Oxidation And Reduction Flashcards
What can oxidation be defined as?
Loss of hydrogen
Gain of oxygen
Loss of electrons
Increase in oxidation state
What can reduction be defined as?
Gain of hydrogen
Loss of oxygen
Gain of electrons
Decrease in oxidation state
What is a redox reaction?
One that involves both oxidation and reduction.
Why do oxidation and reduction occur together?
If something loses electrons something else must gain them.
What does a redox reaction involve?
A change in oxidation state.
What is an oxidising agent?
Species that oxidises other species and in the process is reduced. Oxidising agent remove electrons from something.
What is a reducing agent?
Species that reduces other species and in the process is oxidised. Reducing agents give electrons to something.
How can a group of metals be arranged in order of reactivity?
Magnesium (most reactive strongest reducing agent)
Zinc
Iron
Hydrogen
Copper (least reactive weakest reducing agent but strongest oxidising agent).
What is important about metals higher in the activity series?
They are stronger reducing agents than metals lower in the activity series.
What is important about metals above hydrogen in the activity series?
They are stronger reducing agents than hydrogen and should displace hydrogen from a solution of its ions and acid.
How can a redox equation be broken down?
Into half equations that show the oxidation and reduction processes separately.
How do you balance half reactions?
Balance all atoms except H and O
Add water to side with fewer O atoms to balance O
Add H+ to side with fewer H atoms to balance H
Add e- to side deficient in negative charge to balance charge.
If you are asked to balance an overall redox reaction what is the easiest way to do this?
By splitting it into half equations balance each one individual and then combine them to give the overall equation.
What happens when an oxidation half equation combines with the reduction half equation?
It produces an overall redox equation and the number of electrons lost in the oxidation react must be the same number gained in the reduction reaction.
How do you get the electrons balanced?
By multiplying the half equation by the appropriate numbers.
