a student wants to prepare 200mL of a .970 M CaCl2 solution, starting from a 1.900 M CaCl2 stock solution. What volume of the stock solution will the student need to use to prepare the dilution?

Question

how do i set this up and solve it?

Answer 1

In these types of problems, it can be most effective to utilize the general equation: C₁V₁ = C₂V₂

C₁= 1.900 M CaCl₂ solution

V₁= ??? mL of CaCl₂ solution

C₂= 0.970 M CaCl₂ solution

V₂= 200 mL of CaCl₂ solution

Thus, we plug the values in and solve for the volume needed from your initial concentration of CaCl_2.

(1.900 M CaCl₂ solution) x (X mL of CaCl₂ solution) = (0.970 M CaCl₂ solution) x (200 mL CaCl₂ solution)

X = 102 mL of the initial CaCl₂ solution