The concentration of KBr in a solution prepared by dissolving 2.13 g of KBr in 897 g of water is __________ molal.
A)2.46
B)0.0000207
C)0.0200
D)0.0167
E)0.0186

Question

Quizplus · Accepted Answer

First, we need to calculate the moles of KBr:

moles of KBr = mass of KBr / molar mass of KBr

molar mass of KBr = 39.1 + 79.9 = 119 g/mol
moles of KBr = 2.13 g / 119 g/mol = 0.0179 mol

Now, we need to calculate the mass of water in kilograms:

mass of water = 897 g / 1000 = 0.897 kg

Finally, we can calculate the molality:

molality = moles of solute / mass of solvent in kg

molality = 0.0179 mol / 0.897 kg = 0.0200 mol/kg

Therefore, the concentration of KBr in the solution is 0.0200 molal.

The Concentration of KBr in a Solution Prepared by Dissolving