# Concentrations/ mixing

Ok, Im trying to remember my grade 11 chem stuff cause Im helping out a friend who is taking it, but When you have 2 samples of the same chemical, different volumes and different concentrations then mix them, what formula is used to find the final concentration? is it CiVi + CiVi= CfVf ?

Huzaifa

C1V1 = C2V2

Huzaifa
Thats for dilution. In this question I have 2 samples of the same substance each with a different volume and concentration. Those are then mixed. How do I find the total concentration of the mixture? The final volume will be the sum of the 2 volumes before, but the concentration will be different.

Huzaifa
chem_tr
$$\frac {C_1V_1+C_2V_2}{V_1+V_2}$$