posted by Sam on .
One mole of each of the following compounds is added to water in separate flasks to make 1.0 L of solution. Which solution has the largest total ion concentration?
a. aluminum hydroxide
b. silver chloride
c. sodium chloride
d. calcium carbonate
e. potassium phosphate
I just need help finding out how to calculate the ion concentration of a solution with just the given known. what formula do i need to use for this question?
You don't need a formula and you don't need to calculate the molarity. The problem tells you that you have 1 MOLE of each of the compounds ADDED to H2O to make 1 L of soln.
What you need to know is the solubility of the compound as well as the formula of the compound. For example, the first two are not very soluble at all; therefore, the ionic concn is small (although you CAN calculate the (Al^3+) and (OH^-) from Ksp data and (Ag^+) and (Cl^-) from Ksp data if you wish.) NaCl is quite soluble so the (Na^+) is 1 mole/L and the Cl^- is 1 mole/L for a total of 2 moles ion/L. How soluble is CaCO3? How soluble is K3PO4? If they are soluble to any extent, calculate the concn of the ions in those solns and you will have your answer.
does the ratio between the cation and anion affect the ionic concentration? like, the ratio between K and PO4 is 3:1, so it's more likely that it'll be soluble, in comparison to the Al and OH which is 1:3 (which is not soluble)?
Yes, it does affect the ratio; however, that has little to do with the solubility. Here is a simplified set of solubility rules. You need to memorize these. CaCO3 is largely insoluble. K3PO4 is soluble and ionizes into 3K^+ and 1PO4^3-.http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
Thank you so much!!!