A solution is prepared by dissolving 25.0 g of NaCl in 500.0 g of water.What is the molality (m)of NaCl in the solution? The density of the solution is 1.0 g/mL.
A)0.000856
B)0.0500
C)50.0
D)8.56
E)0.856

Question

Quizplus · Accepted Answer

Molality (m) is calculated as moles of solute per kilogram of solvent. First, calculate moles of NaCl: 25.0 g / 58.44 g/mol = 0.428 moles. Then, convert 500.0 g of water to kg: 500.0 g = 0.500 kg. Finally, molality = 0.428 moles / 0.500 kg = 0.856 m.

A Solution Is Prepared by Dissolving 25