Question

A solution is prepared by dissolving 25.1 g urea, (NH2)2CO, in 170.9 g water. Calculate the boiling point of the solution. Urea is a nonelectrolyte.

Answer 1

101.260 ° C

Step-by-step explanation:

From the given information;

The molarity of lactose solution (m) can be calculated as:

`m = (25.1 * (1 \ mol \ (NH_2)_2 \ CO)/(60.01 g) )/(0.170 \ kg )`

m = 2.46 m

The molar elevation constant of water
`k_b = 0.512 ^0 \ C/m`

Using the elevation in boiling point ;

i.e.

`\Delta T_b = k_b * m`

`\Delta T_b = 0.512 \ ^0C/m * 2.46 \ m`

`\Delta T_b = 1.260 \ ^0C`

The boiling point of water solvent;

`T_(water \ solvent) = 100^0 C`

Elevation in boiling point;

`T_b = T_(solution) - T_(water \ solvent)`

`T_(solution) = T_b+ T_(water \ solvent)`

`T_(solution) = 1.260 \ ^0 C + 100 ^ 0 \ C`

`T_(solution) = 101.260 \ ^0 C`