Question

How do I find the charge of a polyatomic anion? Mickey mouse terms please

Answer 1

You have to remember them
http://en.wikipedia.org/wiki/Polyatomic_ion

Answer 2

it says hydroxide OH- where does that negative come from?

h = -
o = -2 right?

Answer 3

Polyatomic ions exist as compounds and therefore you cannot separate them as you did to find their charge. So you have to remember them as @.Sam. said. Once you encounter these ions, you will get used to them without having to memorise. so just practise.

Answer 4

http://www.physicsforums.com/showthread.php?t=525291Hope it helps:)

Answer 5

so u gt it?

Answer 6

yeah, i wish they would have just put in the hw 'look at the table cause you havnt learned how to figure this out by hand yet'

Answer 7

On my handout it says 'the charge of a polyatomic ion is considered its net oxidation number. The sum of the oxidation numbers of the atoms in a compound musta dd up to the net oxidation number of the polyatomic ion" does this have anything to do wish this? I can't make any sense of it.

Answer 8

wait a minute: -

Answer 9

http://chemistry.about.com/od/generalchemistry/a/oxidationno.htm

Answer 10

now did u gt it?
actually i don't know what u r asking?
but I m only helping u through net^_^

Answer 11

Actually that is true. In your question about OH, O has a charge of -2 while Hydrogen has a charge of +1, so they add up to -1.
So the charge of polyatomic ions should ALWAYS add up.

Answer 12

Thought hydrogen would be -1 though? H - He? or is it a special rule thing

Answer 13

Nope Hydrogen is +1. Look at it's position on the periodic table.

Answer 14

very good @beeqay

Answer 15

All elements in the first group have a charge of +1, while those in group 2 have a charge of +2. Elements in group 7(Halogens) have a charge of -1. So the charge for elements in group 6 would be -2. But it may vary at times.

Answer 16

Thank you @maheshmeghwal9

Answer 17

u deserve it:)

Answer 18

thanks guys

Answer 19

yw:)

Answer 20

No problem.

Answer 21

You can draw the Lewis structure of the ion, then count the number of electrons.
Here you can count 8 electrons.
There should be 6 for O and 1 for H on the valence shell.
So there is one extra electron.