Polyatomic Ion Memorization

Acetate Ion

Chlorate Ion

Answer explanation

The -ate ending means that it has oxygen.

All chlorine group ions have a -1 charge, just like chloride.

Chlorite Ion

Answer explanation

The ion with the -ite suffix has one less oxygen than the ion with the -ate ending, with both overall charges being the same.

To remember the charge, all chlorine group ions have a -1 charge, just like chloride.

Hypochlorite Ion

Answer explanation

The ion with the hypo- prefix has one less oxygen than the ion with the -ite ending, with both overall charges being the same.

To remember the charge, all chlorine group ions have a -1 charge, just like chloride.

Perchlorate Ion

Answer explanation

The ion with the per- prefix has one more oxygen than the ion with the -ate ending, with both overall charges being the same.

To remember the charge, all chlorine group ions have a -1 charge, just like chloride.

Cyanide Ion

Answer explanation

Cyanide will have to be remembered, but note that the letter C and N are in its name.

CyaNide for CN-.

Hydroxide Ion

Answer explanation

Hydroxide is a portmanteau of hydrogen and oxide.

You can think about its charge being a sum of the +1 of H and the -2 of O.

Nitrate Ion

Nitrite ion

Answer explanation

The ion with the -ite ending has one less oxygen than the ion with the -ate ending, with both having the same charges.

Both nitrite and nitrate have a -1 charge.

Permanganate Ion