Question

Match the following aqueous solutions with the appropriate letter from the column on the right.

	1.	0.12 m	AlI3		A.	Highest boiling point
	2.	0.11 m	Cr(NO3)3		B.	Second highest boiling point
	3.	0.14 m	Na2SO4		C.	Third highest boiling point
	4.	0.50 m	Ethylene glycol(nonelectrolyte)		D.	Lowest boiling point

Answer 1

ΔTb = i*Kb*m

ΔTb is the elevation in boiling point

ΔTb will be maximum when i*m is maximum

Boiling temperature is maximum when ΔTb will be maximum

i is the number of ions that a compound can break into

1)

AlI3

i = 4

AlI3 breaks into 1 Al3+ ion and 3 I- ions

so,

i*m = 4*0.12 = 0.48

2)

Cr(NO3)3

i = 4

i*m = 4*0.11 = 0.44

3)

Na2SO4

i=3 as it breaks into 2 Na+ and 1 SO42-

i*m = 3*0.14 = 0.42

4)

i=1 because it is non electrolyte

i*m = 0.50

1. matches to B

2. matches to C

3. matches to D

4. matches to A