How to Calculate Boiling Point of a Solution

What is the boiling point of a solution that contains 3 moles of KBr in 2000 g of water?

A. 97°C
B. 103°C
C. 101.5°C
D. 99.7°C

Answer: C. 101.5°C

The computation of the boiling point of a solution is shown below:

When calculating the boiling point of a solution containing 3 moles of KBr in 2000 g of water, we first need to consider the molality of the solution. Molality (m) is defined as the moles of solute per kilogram of solvent.

Given that the molality of the solution is 0.512°C, we can use the formula [tex]\Delta T = i K_b m[/tex] where i is the Van't Hoff factor, K_b is the boiling point elevation constant, and m is the molality of the solution.

Plugging in the values, we get: [tex](T - 100^{\circ}C) = 2 \times 0.512^{\circ} \times \frac{3.00 \text{ moles}}{2.00 \text{ kg}}[/tex]

After solving the equation, we find that the boiling point of the solution is 101.5°C, which corresponds to option C.