Answer to Question #136232 in Inorganic Chemistry for Faith

Question

What would be the final concentration of a solution containing 20mL of 1.5% NaCl solution diluted to 200mL

Answer 1

density of solution NaCl = 1.0089 g/ml

density of solution = m/V

m₁ solution NaCl = density of solution NaCl * V₁ solution NaCl = 1.0089 * 20 = 20.178 g

mass fraction = (m substance/ m solution) * 100%

m₁ substance NaCl = mass fraction * m₁ solution NaCl = 0.015 * 20.178 = 0.30267 g

V H₂O = V₂ solution - V₁ solution = 200 - 20 = 180 ml

m H₂O = density of H₂O * V H₂O = 1 * 180 = 180 g

mass fraction₂ = m₁ substance NaCl / (m₁ solution NaCl + m H₂O ) = 0.30267/(20.178 + 180) = 0.15%