Chemistry (solutions)

Question

A solution is made by diluting 200 mL of a 1.50 mol/L standard solution to a volume of 400 mL. What is the concentration of the resulting solution?

Answer 1

Use V1C1 = V2C2 or V1M1 = V2M2

V1 = initial volume = 200 ml

C1 or M1 = initial concentration or molarity = 1.5 M

V2 = final volume = 400 ml

C2 or M2 = final concentration of molarity = x M

(200 ml)(1.5 M) = (400 ml)(x M)

x = 0.75 M

You can also see this by looking at the dilution. You are doubling the volume (from 200 ml to 400 ml) so the concentration will be cut in half (1.5 M to 0.75 M)