Question

A chemist wishes to prepare a stock solution of 1.25 M KI. She will be diluting a 3.25 M KI solution in order to obtain 0.355 L of the stock solution. What volume of the 3.25 M solution should she use?

Answer 1

0.137 L of the stock solution

M1V1 = M2V2
M1 = 3.25 M
V1 = This is what we’re solving for.
M2 = 1.25 M
V2 = 0.355 L

Solve for V1 —> V1 = M2V2/M1

V1 = (1.25 M)(0.355 L) / (3.25 M) = 0.137 L