Question

If the density of methanol is 0.793 kg L^-1 , what is its volume needed for making 2.5 L of its 0.25 M solution?

Answer 1

Molar mass of methanol (CH₃OH) = (1×12)+(4×1)+(1×16) = 32 g mol^-1 

= 0.032 kg mol^-1 Molarity of the solution = 0.793/0.032 = 24.78 mol L^-1

Applying, M₁V₁ (Given Solution) = M₂V₂ (Solution to be prepared)

24.78×V₁ = 0.25×2.5 L 

V₁= 0.02522 L = 25.22 mL