December 14, 2019, 12:59:01 AM
Forum Rules: Read This Before Posting


Topic: Is there anyway to memorize common polyatomic ions easily?  (Read 118 times)

0 Members and 1 Guest are viewing this topic.

Offline AppleSnooop

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Is there anyway to memorize common polyatomic ions easily?
« on: November 10, 2019, 10:30:25 PM »
I have a polyatomics quiz in a couple days, my teacher has given us about 15 polyatomics to memorize and I can't do it for the life of me. Is there a certain pattern? Trick?

Offline isaackrementsov

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Is there anyway to memorize common polyatomic ions easily?
« Reply #1 on: November 11, 2019, 12:45:27 AM »
Yes. Although there are a lot of exceptions, the general rule for oxyanions (most polyatomic ions you probably have to memorize) is:
-ate = Some element with some number of oxygens, usually 3. Ex: Chlorate = ClO3-
-ite = The same element with one less oxygen. Ex: Chlorite: ClO2-
hypo- ... -ite = One less oxygen than -ite. Ex: Hypochlorite: ClO-
per- ... -ate = One more oxygen than -ate. Ex: Perchlorate: ClO4-
Changing the number of oxygens in the anion will not change the charge.

Also
Bi-/Hydrogen- = The original ion with a hydrogen attached. Ex: Bisulfate/Hydrogen phosphate = HPO42-
Prefix + Hydrogen- = The ion with some number of hydrogens attached. Ex: Dihydrogen phosphate = H2PO4-
Every hydrogen added will increase the ion's charge by 1.

Other than that, I recommend just creating or running through an existing Quizlet. There are a lot of strange patterns, even with oxyanions, and you do have to remember where the -ate ion is before knowing any of the other forms.

Hope this helped.

Sponsored Links