If a chemist wishes to dilute a 1.000 x 103 mg/l stock solution to prepare 5.000 x 102 ml of a working standard that has a concentration of 6.250 mg/l, what volume of the 1.000 x 103 mg/l standard solution is needed?

Given data:

Concentration of stock solution which is the initial solution = M1 = 1.00 * 10^3 mg/L

Concentration of prepared solution i.e final solution = M2 = 6.250 mg/L

Volume of final solution, V2 = 5.000 * 10^2 ml

To determine:

The initial volume i.e. volume of the stock solution required = V1

Calculation:

Use the relation

M1V1 = M2V2

V1 = M2V2/M1 = 6.250 mg.L-1 * 5.000*10^2 ml/1.00 * 10^3 mg.L-1

V1 = 3.125 *10^3 ml

The volume of stock solution required is 3.125 *10^3 ml

it would be d. henry moseley

hope this !

and sorry if i'm late. have a good rest of your day! : d

it's all four options.