Polyatomic Ions Flashcards
Memorize Table 2.5 for Test 1
Polyatomic ions
- Ions that are themselves composed of two or more atoms linked by the same covalent bonds that hold molecules together… but they have a charge.
- Trick to identify the charge: If the total of the group numbers of the atoms is odd, it will have a charge of 1-. (Except for phosphate, -3.) If the total is even, it will have a charge of 2-.
- -ate has one more Oxygen than -ite.
NH4 +
ammonium
(Note that the only positive common polyatomic ions are this, and hydronium H3O+.
Note that ammonium is different from the compound ammonia, NH3.)
H3O +
hydronium (always in aqueous solutions)
CN -
cyanide
OH -
hydroxide
NO2 -
nitrite
NO3 -
Nitrate
(Hint: Nina, 3 girls. Nitrite is NO2-.)
ClO -
or OCl -
Hypochlorite
(Order: hypochlorite, chlorite, chlorate, perchlorate)
ClO2 -
Chlorite
(Order: hypochlorite, chlorite, chlorate, perchlorate)
ClO3 -
Chlorate
(Order: hypochlorite, chlorite, chlorate, perchlorate)
ClO<span>4</span> -
perchlorate
(Order: hypochlorite, chlorite, chlorate, perchlorate)
MnO4 -
permanganate
C2H3O2 -
acetate
C2O4 2-
oxalate
CO3 2-
carbonate
HCO3 -
hydrogen carbonate
aka bicarbonate ion
SO3 2-
sulfite
HSO3 -
hydrogen sulfite
aka bisulfite
SO4 2-
sulfate
HSO4 -
hydrogen sulfate
aka bisulfate
SCN -
thiocyanate