please help!;
Assuming additivity of volumes, what is the concentration of KBr(in moles/L) in a solution prepared by mixing 2.50x10^2 of 0.0600 Molarity of KBr with 5.00x10^2 ml of 0.0830 Molarity?
I think this is how you do it.
1st: change the mL into L (since M is in mol/L)
2nd: calculate the number of moles of KBr in each solution (M * L from above)
3rd: add the 2 numbers for moles together
4th: add the 2 numbers for volume together
5th: divide since you now have total moles and total volume (M = moles/L)
just a way to check, your answer should be in-between the two given molarities since you are mixing them together and it should be a little closer to the larger molarity since you start with more of it.
try again. It should be between .6M and .083M since those are the values you started with and you are mixing the same compound. What did you get for your 2 new volumes?