Chemistry Question... Due date is quickly approaching & I have been trying to figure this out with no such luck... PLEASE HELP?

First, note that this molecule breaks into three ions - one Ca+2 and two NO3-2

Second, volume times molarity gives moles - 20.0 mL x 1.50 M is 30 millimoles.

3 x 10^-2 moles x 6.02 x 10^23 molecules/mole x 3 ions/molecule is about 5.4 x 10^22 ions.

Check my math (I just SWAGed it) and report the answer to three significant figures.

Solution: Find the number of moles and multiply by Avagadro's Number.

M= moles/Liters

moles= M*Liters

moles= (1.5M)(.02L)= .03 moles of Ca(NO3)2

Now convert from moles to molecules (ions in this case):

.03 x (6.02x10^23) = 1.806x10^22 molecules of Calcium Nitrate

Now when dissolved it will be Ca+2 and NO3- ***NOTE We have 2 nitrate ions for every 1 Calcium*

Multiply the number of molecules by the number of ions:

(1.806x10^22)x3 = 5.418 x 10^22 ions in the solution