Cuál es el punto de ebullición de una solución acuosa de urea al 20 % m/m (20g de soluto por cada 80g de solvente) , si la masa molar de urea es 60 g/mol. (Ke= 0,52 °C/m)

The question is: What is the boiling point of an aqueous solution of urea at 20% m / m (20g of solute for every 80g of solvent), if the molar mass of urea is 60 g / mol. (Kb = 0.52 ° C / m)

The boiling point of given aqueous solution of urea is .

Explanation:

Given: Mass of solute = 20 g

Mass of solvent = 80 g (1 g = 0.001 kg) = 0.08 kg

Molar mass of urea = 60 g

Molality is the number of moles of solute present in a kg of solvent.

Moles is the mass of a substance divided by its molar mass. So, moles of urea is calculated as follows.

Now, molality of given solution is as follows.

Formula used to calculate the boiling point is as follows.

Thus, we can conclude the the boiling point of given aqueous solution of urea is .

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.