Which has the highest, second highest, third highest, and lowest boiling points?
1.0.20 m MnSO4
2.9.6E-2 m Al2(SO4)3
3.8.4E-2 m Al2(SO4)3
4. 0.45 m Sucrose(nonelectrolyte)
[I know it is m times i but not sure how to get "i"]
I assume you mean boiling point as in solutions and not boiling point of the pure material.
i is the van't Hoff factor and is the number of particles
MnSO4 ==> Mn^2+ + SO4^2- so i = 2
To find the molality (m) times the van't Hoff factor (i) for each substance, you need to determine the number of particles a substance dissociates into when it dissolves in water.
1.0.20 m MnSO4:
MnSO4 dissociates into one Mn2+ ion and one SO4^2- ion, so the van't Hoff factor (i) for MnSO4 is 2.
2.9.6E-2 m Al2(SO4)3:
Al2(SO4)3 dissociates into two Al^3+ ions and three SO4^2- ions, so the van't Hoff factor (i) for Al2(SO4)3 is 5.
3.8.4E-2 m Al2(SO4)3:
As mentioned above, Al2(SO4)3 dissociates into two Al^3+ ions and three SO4^2- ions, so the van't Hoff factor (i) for Al2(SO4)3 is 5.
4.0.45 m Sucrose(nonelectrolyte):
Sucrose does not dissociate into ions when it dissolves in water, so the van't Hoff factor (i) for sucrose is 1.
Now that we have the values for the van't Hoff factor (i) for each substance, we can calculate the molality (m) times the van't Hoff factor (i) for each substance:
1.0.20 m MnSO4: 0.20 * 2 = 0.40
2.9.6E-2 m Al2(SO4)3: 9.6E-2 * 5 = 4.8E-1
3.8.4E-2 m Al2(SO4)3: 8.4E-2 * 5 = 4.2E-1
4.0.45 m Sucrose(nonelectrolyte): 0.45 * 1 = 0.45
Now, let's compare the values:
Highest boiling point: 9.6E-2 m Al2(SO4)3 (4.8E-1)
Second highest boiling point: 8.4E-2 m Al2(SO4)3 (4.2E-1)
Third highest boiling point: 0.45 m Sucrose(nonelectrolyte)
Lowest boiling point: 0.20 m MnSO4 (0.40)
Note: The highest the molality (m) times the van't Hoff factor (i), the higher the boiling point.