Oxidation, reducing and redox reactions

define oxidation in terms of electrons

loss of electrons

define oxidation in terms of oxygen

gain of oxygen

define oxidation in terms of hydrogen

loss of hydrogen

define reduction in terms of electrons

gain of electrons

define reduction in terms of oxygen

loss of oxygen

define reduction in terms of hydrogen

gain of hydrogen

what is an oxidising agent?

an electron acceptor, gets reduces

what is a reducing agent?

electron donor, is oxidised

what is a redox reaction?

reaction where oxidation and reduction occurs, oxidation states change

what is a disproportionation reaction?

A redox reaction in which the same element is both oxidised and reduced

how are all disproportionation reactions redox reactions?

they all involve changes in oxidation states

if an element is oxidised, how does the oxidation state change?

increases;

e.g. 0 to +2

if an element is reduced, how does the oxidation state change?

decreases

rules for oxidation states?

1. Any element/diatomic by itself = 0

2. Monoatomic ions = 0

3. compounds: sum of oxidation states = charge

4. group 1 atoms = +1

5. group 2 atoms = +2

6. fluorine = -1

7. hydrogen = +1

8. oxygen = -2

9. chlorine = -1

10. rule 8 is overruled by 7, rules 7-9 are overruled by earlier ones; e.g. oxygen in H2O2 has an O state of -1

how to balance simple half equations?

1 balance atoms

2 balance charge with electrons

how to balance complex half equations?

1 balance atoms

2 to balance oxygen, add water

3 to balance hydrogen, add protons (H+)

4 balance electrons and charges

(protons and electrons are always on the same side)

steps to writing a net ionic equation?

1) Write the balanced molecular equation.

2) Write the balanced complete ionic equation (dissociation).

3) Cross out the spectator ions that are present.

4) Write the "leftovers" as the net ionic equation.

state symbols!!!

what is dissociation?

when an ionic compound dissolves in water, the ions separate and move around independentley

what are spectator ions?

ions in solution that are present but are unchanged by the reaction, charges stay the same

what is the net ionic equation?

an ionic equation where the spectator ions are removed

what is a complete ionic equation?

an equation that shows dissolved ionic compounds as dissociated free ions, they need balanced charges on each side