Answer:
Weight percent = 29.5%
Molality = 2.460 mol/kg
Mole fraction = 0.042
Explanation:
The weight percent (%w) of a substance is the mass of it divided by the total mass of the solution, and then multiplied by 100%, so:
%w = [44.5/(44.5 + 106.5)] *100%
%w = 29.5%
The molality (W) of a solution is the number of moles of the solute divided by the mass (in kg) of the solvent. In this case, water is the solvent, and AgNO₃ the solute (water is generally the solvent, and the solvent is always in a larger amount). The number of moles is the mass divided by the molar mass, and the molar mass of AgNO₃ is 169.87 g/mol:
n = 44.5/169.87 = 0.2620 mol
W = 0.2620/0.1065 = 2.460 mol/kg
The mole fraction (x) of a substance is the number of moles of it divided by the total number of moles of the solution. The molar mass of water is 18 g/mol, so the number of moles of water is:
n = 106.5/18 = 5.92 moles
Thus the mole fraction of AgNO₃ is:
x = 0.2620/(0.2620 + 5.92) = 0.042
