Chemists who analyze samples for trace metals may buy standard solutions that contain 1000.0 mg/l concentrations of the metals.
if a chemist wishes to dilute a 1.000 × 10^3 mg/l stock solution to prepare 5.000 × 10^2 ml of a working standard that has a concentration of 7.000 mg/l, what volume of the 1.000 × 10^3 mg/l standard solution is needed?