Mixed 250 g of a 30% aqueous solution of methanol and 300 g of a 40% solution

Mixed 250 g of a 30% aqueous solution of methanol and 300 g of a 40% solution of the same alcohol. Find the mass fraction in% of alcohol and the final mixture.

The mass fraction of a substance in a mixture after mixing two solutions is determined by the formula:

W (in-va) = W1 • m1 + W2 • m2 / m1 + m2.

where m1 and m2 are the masses of solutions, and W1 and W2 are the corresponding concentrations.

The alcohol concentration will be equal to:

W (CH3OH) = (30 * 250) + (40 * 300) / 250 + 300 = 35.5%.