Oxidation State

Question 1

rules for calculating oxidation number

Answer 1

elemental form: always 0
monoatomic ion: charge
oxygen: usually -2 except peroxides (-1)
hydrogen: usu +1 w non-metals, -1 w metal ions
fluorine: -1 in all compounds
neutral compound: sum 0
polyatomic ion: sum charge

Question 2

common oxidation states of elements n their compounds

Answer 2

grp 1 metal ion: +1
grp 2 metal ion: +2
grp 3 metal ion: +3
hydrogen: +1 (non-metal), -1 (metal ions/hydrides)
fluorine: -1 in all compounds
oxygen: -2, -1 in peroxide, +2 with F
chlorine: -1, +1 with F, or positive with O

Question 3

statement

Answer 3

hm is oxidised/reduced as the oxidation state of hm increases/decreases from ? in <> to ? in <>
(since hm is oxidised and hm is reduced, this is a redox reaction.)

*write “ion” if it’s ion

Question 4

disproportionation reaction

Answer 4

a disproportionation reaction occurs when a substance is both oxidised and reduced simultaneously to form 2 different products