Active mass: Concentration of a substance expressed usually in moles per liter. (Molarity basically)
Number of moles =440=0.1 moles
V=500 ml=0.5 litres
Molarity / Active mass =0.10.5=0.2 mol/litre
8 g NaOH is dissolved in water to make one litre solution, its molarity is
0.2 mole of HCl and 0.1 mole of CaCl2 were dissolved in water to have 500 ml of solution, the molarity of Cl- ions is
(1)0.04 M (2)0.8 M (3)0.4 M (4)0.08 M