3.1.7 -oxidation, Reduction And Redox Equations Flashcards
What are the oxidation states of atoms and simple ions ?
The number of electrons which must be added or removed to become neutral
What should the oxidation states do in molecules
Sum of the oxidation states should add up to 0
What is the oxidation states of c and o in co2
C is +4
O is -2
What should the oxidation states be in a complex ion
The sum of the oxidation states should add up to the charge on the ion
What are the bench marks
Hydrogen (+1)
Oxygen (-2)
Fluorine (-1)
What is the exception of hydrogen to the bench mark
It’s 0 in H and H2
-1 in hydride ion eg NaH
What’s the exception of oxygen in the bench marks
It’s 0 in O and O2
-1 in hydrogen peroxide
+2 in F2O
What is the exception in fluorine to the bench mark
0 in F and F2
What are the usual oxidation values of metals
- usually postive values
- can go up to the group number
What are the normal oxidation states of non- metals
Mostly negative
Values up to group number
Define redox
When reduction and oxidation takes place
Define oxidation
Removal of electrons
Na—> Na+
Define reduction
Gain of electrons
Cl—> Cl-
Define oxidising agent
Accepts electrons
Define reducing agent
Donates electrons
What is OIL RIG
Oxidation Is Loss
Reduction Is Gain
Steps to balancing half equations
1) balance the atoms
2) add H+ or H20 to balance atoms
3) add electrons to balance charge on each side
Steps to combining half equations to make redox equations
1) multiply to make electrons the same
2) write the redox equation
