Question

List the following aqueous solutions in order of increasing boiling point: 0.12 m C6H12O6, 0.05 m LiBr, and 0.05 m Zn(NO3)2. Explain your order.List the following aqueous solutions in order of increasing boiling point: 0.12 m C6H12O6, 0.05 m LiBr, and 0.05 m Zn(NO3)2. Explain your order.

Answer 1

Answer: The order of increasing boiling points follows:

`\text{LiBr }<C_6H_(12)O_6<Zn(NO_3)_2`

Step-by-step explanation:

The expression of elevation in boiling point is given as:

`\Delta T_b=i* k_b* m`

where,

`\Delta T_b` = Elevation in boiling point

i = Van't Hoff factor

`T_b` = change in boiling point

`k_b` = boiling point constant

m = molality

For the given options:

• Option 1: 0.12 m
  `C_6H_(12)O_6`

Value of i = 1 (for non-electrolytes)

So, molal concentration will be =
`(0.12)* 1=0.12m`

• Option 2: 0.02 m LiBr

Value of i = 2

So, molal concentration will be =
`(0.02)* 2=0.04m`

• Option 3: 0.05 m
  `Zn(NO_3)_2`

Value of i = 3

So, molal concentration will be =
`(0.05)* 3=0.15m`

As, the molal concentration of
`Zn(NO_3)_2` is the highest, so its boiling point will be the highest.

Hence, the order of increasing boiling points follows:

`\text{LiBr }<C_6H_(12)O_6<Zn(NO_3)_2`