Calculate the molality of a 10.0% (by mass)aqueous solution of hydrochloric acid.
A)3.32 m
B)121 m
C)1.10 m
D)1.66 m
E)The density of the solution is needed to solve the problem.

Question

Quizplus · Accepted Answer

Molality (m) is calculated using the formula: m = moles of solute / kg of solvent. For a 10% HCl solution, there are 10 g of HCl in 100 g of solution, meaning 90 g of water. The molar mass of HCl is 36.46 g/mol, so moles of HCl = 10 g / 36.46 g/mol = 0.274 mol. The mass of water is 0.090 kg. Thus, molality = 0.274 mol / 0.090 kg = 3.32 m.

Calculate the Molality of a 10