Methyl alcohol with a volume of 40 ml and a density of 0.8 g / ml was dissolved in water with a mass of 128 g

Methyl alcohol with a volume of 40 ml and a density of 0.8 g / ml was dissolved in water with a mass of 128 g, determine the molar concentration of the resulting solution if its density is 0.97 g / ml.

1. Find the mass and chemical amount of methyl alcohol:

m (CH3OH) = V (CH3OH) * ρ (CH3OH) = 40 ml * 0.8 g / ml = 32 g.

n (CH3OH) = m (CH3OH) / M (CH3OH) = 32 g / 32 g / mol = 1 mol.

2. Find the mass, and then the volume of the resulting solution:

m (solution) = m (solution) + m (CH3OH) = 128 g + 32 g = 160 g.

V (solution) = m (solution) / ρ (solution) = 160 g * 0.97 g / ml = 165 ml.

165 ml = 0.165 l.

3. Find the molar concentration of the resulting solution:

c (solution) = n (CH3OH) / V (solution) = 1 mol / 0.165 L = 6.06 mol / L.

Answer: c (solution) = 6.06 mol / l.