Question

Choose the aqueous solution below with the lowest freezing point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

0.075 m KNO2
0.075 m (NH4)3PO4
0.075 m NaBrO4
0.075 m KCN
0.075 m Li Cl

Answer 1

Step-by-step explanation:

All the given solution has equal concentration of solute so the depression in freezing point will depend upon the van't Hoff factors . If we treat all as strong electrolyte

the van't Hoff factor of KNO₂ = 2 (1 + 1 )

(NH4)₃PO4 = 4 ( 3 +1 )

NaBrO4 = 2 ( 1 + 1 )

KCN = 2

LiCl = 2

So van't Hoff factor is largest in NH4)₃PO4 so depression in freeing point will be largest in it so lowest freezing point of water will be in case of solution of NH4)₃PO4 .