Question

0.1gram mole of urea dissolved in 100 g of water. The molality of the solution is

Answer 1

Answer : The Molality of solution is 0.01665 mole/g.

Solution : Given,

Mass of urea = 0.1 gram

Mass of water = 100 gram

Molar mass of urea = 60.06 g/mole

Molality : It is defined as the number of moles of solute present in one kilogram of solvent.

Formula used :

$Molality=\frac{W_{urea}\times 1000}{M_{urea}\times W_{water}}$

where,

$W_{urea}$ = mass of urea

$W_{water}$ = mass of water

$M_{urea}$ = molar mass of urea

Now put all the given values in above formula, we get

$Molality=\frac{0.1g\times 1000}{60.06g/mole\times 100g}$ = 0.01665 mole/g

Therefore, the molality of solution is 0.01665 mole/g.