Which of the following aqueous solutions will have the lowes

Which of the following aqueous solutions will have the lowest freezing point?

a. 0.5 m C12H22O11 (sucrose)

b. 0.5 m Ca(NO3)2

c. 0.5 m NiSO4

d. 0.5 m Li3PO4

e. 0.5 m KCl

Answer is D - need explanation - thanks!

deltaT = Kf*M*i ( M = molality , i = vant hoff factor)

molality is same for all,

now i depends on no of ions in which the solute dissociates,

i.e for NaCl , i = 2

therefore,

Li3PO4 dissociate in most no of ions = 4

and has the highest van toff factor,

delta T for Li3PO4 is the highest,

therefore, lowest freezing pt.