An aqueous solution of sodium chloride is marked `10%(w//w)` on the bottle. The density of the solution is `1.071 gmL^(-1)`. What is the molity and molarity? Also, what is the mole fraction of each components in the solution?

Explanation

`100 g` solution contains `10 g NaCl`
`w= 10 g, m_(NaCl)= 58.5`,
Volume of solution `=(100)/(1.071xx1000)"litre"`
`w_(H_(2))o= 100-10= 90 g`
`"Molarity"=("Wt.of soulute")/("mol.wt.of solute"xxV_("in"L))`
`=(10xx1.071xx1000)/(58.5xx100)=1.83M`
`"Molality"=("Wt.of solute")/("mol.wt.of solute" xx "weight of solvent in kg")`
`=(10xx1000)/(58.5xx90)=1.90 m`
Mole fraction of `NaCl=(w//m)/((w)/(m)+(W)/(M))=(10//58.5)/((10)/(58.5)+(90)/(18))= 0.03`
Mole fraction of `H_(2)O=1-0.03= 0.97`