What volume of methanol should be used to make 1.25 L of a 21.0% by volume solution?

___ mL

V CH3OH = 262.5 mL

Explanation:

%v/v = (v compound / v sln) * 100

∴ %v/v = 21.0 %

∴ v sln = 1.25 L

⇒ v compound = ?

⇒ 21.0 % = (v compound / 1.25) * 100

⇒ 0.21 = v compound / 1.25 L

⇒ (0.21) * (1.25 L) = v compound

⇒ v compound = 0.2625 L = 262.5 mL