A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution ? If the density of the solution is 1.2 g `mL^(-1)` , then what shall be the molarity of the solution ?

Explanation

10% w/w means 10 g glucose is present in 100 g solution,
Mass of water = 100 – 10 = 90 g = 0.09 kg 10
10 g glucose = 10/180 mol = 0.0555 mol
Number of moles in 90 g `H_2O = 90/18 = 5` moles
Molality of solution = 0.0555 mol / 0.090 kg = 0.617 m
Mole fraction of glucose ` = (0.0555)/(5 + 0.0555) = 0.01`
mole of fraction of `H_2O = 1 - 0.01 = 0.99`
Volume of 100 g solution = 100/1.2 mL = 83.33 mL = 0.08333 L
` therefore ` molarity ` = (0.0555)/(0.08333L) = 0.67 M`