4.0 g of NaOH are present in one decilitre of solution . Calcute
Mole fraction of NaOH
Molality of solution
Molarity of solution.

Answer

(i) 0.018 (ii) 1M (iii) 0.0043

Explanation

Moles of NaOH `= (4.0)/(40) = 0.1`
Volume of solution = 100 mL
Mass of water `= 103.8-40 = 99.8 g`
Moles of water ` = (99.8)/(18) = 5.54`
(i) Mole fraction of NaOH `= (0.1)/(0.1+5.54) = 0.018`
(ii) Molarity ` = (0.1)/(100) xx 1000 = 1 M`
Molality `= (0.1)/(99.8) xx 1000 = 1.002 `M