# dr bob

posted by .

I am still confused by the last one CO3^2-

You were nice enough to do a diagram and then the expalnation for what else I needed to do was so confusing - I am at study hall and this is my last one

• dr bob -

You have 24 electrons.
O
|
C=O
|
O
For every dash in the diagram above place two electrons. Around the top O place three sets of two electrons (3 pairs)l Same thing for bottom O. For middle O, place two more pairs. Count the electrons. You should have 24. Now show a 2- charge on the entire ion.

• dr bob -

I am just not getting this one is it possible to make the drawing if it HELP

• dr bob -

What's the problem? Just not getting doesn't help me much. I've done it two ways and you are still having problem. Do you not understand why we have 24 electrons? Do you not understand why we have 4 bonds? Just what is it you don't get? Be specific. Be detailed. Don't leave out anything.

• dr bob -

I cant seem to get the diagram right on this one - I am sorry

• dr bob -

What's not right about the diagram? How do you know it isn't right?

• dr bob -

where does the 2- go

• dr bob -

The 2- is just the charge on the carbonate ion (CO3^2-). So you can put large parentheses around the diagram [left and right-- like this--(diagram)] and put the 2- at the upper right of the right hand parenthesis. Some people don't even put the parenthese--they just place a 2- in the upper part of the diagram but off a little to one side. Like this
O
|
C=O
|
O

• dr bob -

The 2- didn't print. Let me try again.
O    2-
|
C=O
|
O

• dr bob -

so it is not nec for the parenthesis

• dr bob -

Not really. I think it makes it neater because the 2- isn't just sticking out there. However, I've seen it done both ways.

• dr bob -

you are very generous with your time thanks sam

• dr bob -

You're most welcome. Keep posting.