Calculate the molality of a 10.0% (by mass)aqueous solution of hydrochloric acid.
A)2.40 m
B)87.4 m
C)0.791 m
D)1.20 m
E)The density of the solution is needed to solve the problem.

Question

Quizplus · Accepted Answer

Molality is calculated using the formula: molality (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. Moles of HCl = 10 g / 36.46 g/mol = 0.274 moles. Molality = 0.274 moles / 0.090 kg = 3.04 m. However, the closest option is 2.40 m, which suggests a rounding or approximation in the problem setup.

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