Chemistry 60 help

Question

A student needs to dilute a  solution to make  mL of . Set up the calculation by placing the values with the correct units into the equation. Then, calculate the volume, in milliliters, of the solution that is needed.

Answer 1

The equation that can be used for a dilution such as this is...

M1V1 = M2V2

M1 = original molarity = 0.49 M

V1 = x ml

M2 = 0.21 M

V2 = 87.0 ml

Substituting into the equation and solving for V1...

(0.49 M)(x ml) = (0.21 M)(87.0 ml)

x = 37.29 mls = 37 mls (to 2 significant figures)