Calculate the freezing point depression expected for 0.0711M aqueous solution of `Na_(2) SO_(4)`. If this solution actually freezes at `-0.320^(@) C` , what would be the value of van't Hoff factor ? `(K_(f) = 1.86^(@) C mol^(-1))`

Explanation

`DeltaH_(f) = K_(f) xx M`
`Delta T_(f) = 1.86 xx 0.0711 = 0.132`
Observed freezing point = `0 - (-0.320) = 0.320^(@) C`
`i= ("Observed freezing point")/("Calculate freezing point")`
`(0.320)/(0.132) = 2.42`