Question

WHY can't I use M1V1+ M2V2= M3V3 in this question??

"What is the concentration of NO3-ions when equal
volumes of 0.1 M AgNO3 and 0.1 M NaCl are
mixed together?"
(1) 0.1 N.
(2) 0.25 M
(3) 0.05 M.
(4) 0.2 M
( I know the answer and method I just want to know why the answer throughthe formula m1v1+m2v2=m3v3 is wrong?)​

Answer 1

Answer:

because

Explanation:

Kind of, but not exactly. M1V1=M2V2 only applies when you are not changing the number of moles in the final solution. What you need is more like M1V1 + M2V2 = M3V3, that is, moles in the first solution plus moles in the second equals moles in the mixed (third) solution.