RULES for OXIDATION NUMBERS O.N. (see Kotz, p. 191)
RULES for OXIDATION NUMBERS O.N. (see Kotz, p. 191)
- Atoms in pure ELEMENT (Cu, I2, S8) 0
- Ions of single atom (Al#+) charge on ion
- Fluorine in compounds (NaF) -1
- other halogens in compounds (KCl, CsI) -1
- EXCEPT when combined with F or O where O.N. = +1
- hydrogen in most compounds (HCl, HI) +1
- EXCEPT metal hydrides (CaH2) where O.N. = -1
- oxygen in most compounds (MgO, Na2O) -2
- EXCEPT in peroxides (H2O2) where O.N. = -1
- the O.N. of all other elements in a compound are determined by
requiring that
SUM of O.N. of all elements = CHARGE on the compound