Question

What volume of 2.5% (m/v) KOH can be prepared from 125 mL of a 5.0% KOH solution?

Answer 1

Hey there!:

According to lew of dilution :

M*V = M'*V'

Where :

M = concentration of stock solution =  5.0% ( m / V )

V = volume of stock solution = 125 mL

M' = concentration of dilute solution = 2.5% ( m/V)

V' = volume of dilute solution = ??

Plug the values  we get:

V' =  m*V / M'

V' =  5.0 * 125 / 2.5

V' = 625 / 2.5

V' = 250 mL

Therefore , the volume prepared is 250 mL

Hope that helps!