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 solution 1.2 g `mL^(-1)`, then what shall be the molarity of the solution?

Answer

`0.67M`

Explanation

Let us suppose that the mass of solution is `100g`
Since solution is `10%` glucose , therefore the mass of solvent is `100-10=90g`
Molar mass of glucose, `C_(6)H_(12)O_(6)=72+12+96`
`=180g mol`
`m=(W_(2)xx1000)/(Mw_(2)xxW_(1))=(10xx1000)/(180xx90)=0.617m`
Moles of water`=(90)/(18)=5`
Moles of glucose `=(10)/(180)=0.055mol`
Mole fraction of glucose `(CHMi_(2))=(0.055)/(5+0.55)=0.01`
Mole fraction of water `(CHMi_(1))=1-0.01=0.99`
`V_(sol)=(W_(sol))/(d_(sol))=(100)/(1.2)=83.33mL`
`M=(W_(2)xx1000)/(Mw_(2)xxV_(sol i n mL))`
`=(n_(2)xx1000)/(V_(sol i n mL))`
`=(0.055xx1000)/(83.33)=0.67M`