Oxidation and Reduction Flashcards
What is oxidisation?
- The addition of oxygen.
- There is a loss of electrons.
- There is an increase in oxidation number.
What is reduction?
- The loss of oxygen.
- The gaining of electrons.
- A decrease in oxidation number.
What is an oxidising agent?
A substance that causes oxidation. The oxidation agent takes the electrons and is therefore reduced in the process (since it gains electrons).
What is a reducing agent?
A substance that causes reduction. The reducing agent supplies the electrons and is therefore oxidised in the process (since it loses the electrons).
What is oxidation number?
Oxidation number is the charge which an atom of an element has, or appears to have, in a compound.
In the equation, Zn + Cu2+ —> Zn2+ + Cu. Which of the products are the reducing/oxidising agent?
Zn2+ is the reduction agent and Cu is the oxidisation agent.
What’s the oxidation number for any un combined element?
0.
What’s the oxidation number for an ion with a charge?
The oxidation number is the same as its charge.
What’s the oxidation number for a compound?
It must equal to 0.
What’s the oxidation number for hydrogen?
Normally 1 except for when it’s bonded to elements in group 1/2, then it’s -1.
What’s the oxidation number for oxygen?
- 2, but there are two exceptions:
- H2O2 which is -1.
- OF2 which is 2.
What’s the oxidation number for halogens?
-1, unless bonded with a more electronegative element
What’s the oxidation number for a complex ion?
The same as its charge.
How do you balance redox equations?
- Assign oxidation numbers to all atoms.
- Identify the atoms being oxidised and reduced.
- Get the difference in oxidation number between the oxidised and reduced atoms.
- The two differences will act as a ratio.
- Swap and apply the ratio to the equation.
- Check that each side is balanced.
Give one example of oxidising agent.
Potassium permanganate.
