Soru
Consider naphthalene, C_(10)H_(8) , the active ingredient of moth balls. A solution of naphthalene is prepared by mixing 25.0 g of naphthalene with 0750 L of carbon disulfide, CS_(2)(d=1.263g/mL ). Assume that the volume of the solu- tion is the same as that of the solvent after the solution is prepared. (a) What is the mass percent of naphthalene in the solution? (b) What is the concentration of naphthalene in parts per million? (c) What is the density of the solution? (d) What is the molarity of the solution? Answers (e) What is the molality of the solution? (a)
Çözüm
4.3
(232 Oylar)
Irfan
Profesyonel · 6 yıl öğretmeni
Uzman doğrulaması
Cevap
To find the mass percent of naphthalene in the solution, we need to calculate the total mass of the solution and then find the percentage of the total mass that is due to naphthalene.Given:- Mass of naphthalene = 25.0 g- Volume of carbon disulfide (solvent) = 750 mL- Density of carbon disulfide = 1.263 g/mLStep 1: Calculate the mass of the solvent (carbon disulfide).Mass of carbon disulfide = Density × VolumeMass of carbon disulfide = 1.263 g/mL × 750 mLMass of carbon disulfide = 943.5 gStep 2: Calculate the total mass of the solution.Total mass of the solution = Mass of naphthalene + Mass of carbon disulfideTotal mass of the solution = 25.0 g + 943.5 gTotal mass of the solution = 968.5 gStep 3: Calculate the mass percent of naphthalene in the solution.Mass percent of naphthalene = (Mass of naphthalene / Total mass of the solution) × 100Mass percent of naphthalene = (25.0 g / 968.5 g) × 100Mass percent of naphthalene ≈ 2.58%Therefore, the mass percent of naphthalene in the solution is approximately 2.58%.