Respuesta :
To solve this we use the equation,
M1V1 = M2V2
where M1 is the concentration of the stock solution, V1 is the volume of the stock solution, M2 is the concentration of the new solution and V2 is its volume.
.675 M x V1 = .25 M x 1.3 L
V1 = 0.48 L or 480 mL
If a chemist wants to make 1.3 L of 0.25 M solution of KOH by diluting a stock solution of 0.675 M KOH, the chemist would need to use 480 mL of the stock solution.