Question

Choose the solution that has the same effect on the freezing point of an aqueous solution as 0.20 M Al(NO3)3(aq).

  A) 0.30 M SrCl2(aq)

B) 0.50 M CaCl2(aq)

C) 0.20 M CH3OH(aq)

D) 0.10 M AlPO4(aq)

E) 0.40 M KCl(aq)

Answer 1

Answer – We are given the 0.20 M Al(NO₃)₃(aq) and we need to choose the solution that has the same effect on the freezing point.

We know, for the freezing point of an aqueous solution we need the same freezing point depression and for the same freezing point depression we need same van't hoff factor and molality. So for the given solution that has the same effect on the freezing point. We need 0.20 M concentration and van't hoff factor

4 or we need 0.4 M and van't hoff factor 2.

So answer for this is- E) 0.40 M KCl(aq), since it has 0.4 M concentration and 2 van't hoff factor.