1) Concentrated hydrochloric acid is an aqueous solution that is 37.2 % HCl by m

Question

1) Concentrated hydrochloric acid is an aqueous solution that is 37.2 % HCl by mass. The density of the solution is 1.19 g/mL. What mass of HCl is contained in 0.646 L of solution?

2)Calculate the molality of a sucrose solution made by dissolving 39 grams sucrose into 97.7 grams water. The molar mass of sucrose is 342.2 g/mol.

3) Calculate the concentration in ppm of lead in a solution that contains 140.26 mg Pb per 4.26 kg of solution.

4) What is the freezing point of 0.30m aqueous glucose? (The molar mass of glucose is 180.16g/mol. The Kf for water is 1.86 C/m.)

Please Help

Explanation / Answer

1)

mass % = 37.2 %

density = 1.19 g/mL

Molarity = mass % x density x 10 / molar mass

              = 37.2 x 1.19 x 10 / 36. 5

              = 12.13 M

Molarity = moles / volume

12.13 = moles / 0.646

moles of HCl = 7.835

mass of HCl = 286 g

2)

moles of sucrose = 39 / 342.2 = 0.114 mol

molality = moles / mass of solvent

             = 0.114 / 0.0977

molality = 1.17 m

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