Question

Which one of the following $0.06\, M$ aqueous solutions has lowest freezing point?

• A. $Al _{2}\left( SO _{4}\right)_{3}$
• B. $C _{6} H _{12} O _{6}$
• C. $KI$
• D. $K _{2} SO _{4}$

Answer 1

Answer: (A)

$T_{f}-T_{f}^{\prime}=i K_{f} m$
For minimum $T_{f}^{\prime}$
'$i$' should be maximum.
$Al _{2}\left( SO _{4}\right)_{3} \,\, i=5 $
$C _{6} H _{12} O _{6} \,\, i=1 $
$KI \,\, i=2 $
$K _{2} SO _{4} \, \,i=3$