Answer to Question #57789 in General Chemistry for tracy guido

Question

Three aqueous solutions are made, FeCl2, NaCl, Na2S all of which have the same molarity. Which two solutions will have the same freezing point depression? Hint: Tb = i x kb)
a. FeCl2 and Na2S FeCl2 = Fe+2 and 2 Cl- = 1+2 = 3 Na2S = 2Na+ and S-2 = 2+1 = 3
b. FeCl2 and NaCl FeCl2 = Fe+2 and 2 Cl- = 1+2 = 3 NaCl = Na+ and Cl- = 1+1 = 2
c. Na2S and NaCl Na2S = 2Na+ and S-2 = 2+1 = 3 NaCl = Na+ and Cl- = 1+1 = 2
I believe it would be a because the i is same for both

Answer 1

Your assumption is 100% correct!
FeCl2 and Na2S solutions contain the same concentration of ions. Therefore temperature depression will be equal.