REDOX Flashcards
What is oxidation and reduction in terms of oxygen?
Oxidation is the GAIN of oxygen
Reduction is the LOSE of oxygen
What is oxidation and reduction in terms of electrons?
Oxidation is the lose of electrons
Reduction is the gain of electrons
How can you tell which element is thought to have oxidised/ reduced in a covalent compound? E.g, water
In the molecule H2O the bonding electrons in the 2 O-H bonds are NOT EQUALLY shared
- The oxygen attracts the electrons more; has gained an increased share; is thought to have been REDUCED
- The hydrogen attracts the electrons less; has a lesser share; is thought to have OXIDISED
What are the rules for assigning oxidation states to atoms?
- The oxidation state of an atom in its elemental state is 0
- The oxidation state of a monatomic ion is equal to the charge on the ion
- The sum of the oxidation states of all atoms in a poly-atomic ion is equal to the charge on the ion
- The oxidation state of a Group 1 metal atom in a compound is +1
- The oxidation state of a Group 2 metal atom in a a compound is +2
- The oxidation state of an oxygen atom is almost always -2
- The oxidation state of a hydrogen atom in a compound is almost always +1
In a reaction what does an elements change in oxidation state tell you about the way they’ve reacted?
- If in a reaction an element INCREASES its oxidation state, it has been OXIDISED
- If in a reaction an element DECREASES, its oxidation state it has been REDUCED
What is meant by the term “disproportionation”?
Disproportionation is a type of REDOX reaction in which a single species is SIMULTANEOUSLY both oxidised AND reduced
What is an oxidising agent? How can you spot an oxidising agent?
- Oxidising agents GIVE OXYGEN to another substance
- become REDUCED
- Gain/accept the electrons that are lost
What is a reducing agent? How can you spot a reducing agent?
- Reducing agents REMOVE oxygen from another substance
- become OXIDISED
- Lose/ supply the electrons that are gained
