0.275gAgNO3 is dissolved in 500mL of solution.

Question

a. What is the molarity of this solution.
b. If 10.0 mL of this solution are transferred to a flask and diluted to 500mL, what is the concentration of the resulting solution?
c. If 10.0mL of the solution in (b) are transferred to a flask and diluted to 250mL, what is the concentration of the resulting solution?

I got the molarity = .00162moleAgNO3 / .5L = .00324

I do not know how to do concentrations. I know it's the amount of solute / amount of solvent or solution but I do not know how to determine these. Can you please explain this to me? Thanks

Answer 1

a is right.
b and c. There is more than one way to do these. The easiest, I think, is to see what the factor is; i.e., you are diluting 10 mL to 500 so the new concn is
0.0324 x (10/500) = ?
Then c is answer from a x (10/250) = ?

Another way is to use the definition of molarity or M = mols/L.
How many mols do you have in the 10 mL of part a? That's mols = M x L.
Then the molarity of that solution in 500 mL is mols/0.5 L = ? Actually the numbers inserted are exactly the same but the thought process is different.