At T K xg of a non-volatile solid (molar mass 78 g mol - 1 ) when added to 0 . 5 kg water, lowered its freezing point by 1 . 0 ° C . What is x (in g ) ( K f of water at T ( K ) = 1 . 86 KKgmol - 1 )

Step-by-step solution

Depression in freezing point is a colligative property.Hence, it depends on the number of solute particles. ΔT f = K f × m m=Molality ΔT f = Freezing point of solvent - Freezing point of solution ΔT f = 1 . 0 ∘ C ΔT f = 1 . 88 × m 1 . 0 = 1 . 88 × x 78 × 1000 500 x = 20 . 96   g Hence, the weight of non-volatile solid is 20.96grams