Question

When diluting 25 grams of table salt in 250 ml of water, by how many °C does the boiling point of the formed solution increase? (Ke = 0.52 °C / molal, MW NaCl = 58.44 g / mol)

a. 1.52 °C
b. 2.52 °C
c. 0.52 °C
d. 3.52 °C

Answer 1

When diluting 25 grams of table salt in 250 ml of water, the boiling point of the formed solution will increase by approximately 0.8928 °C.

Step-by-step explanation:

When diluting 25 grams of table salt in 250 ml of water, the boiling point of the formed solution will increase. The molal boiling point elevation constant for water is 0.52°C/m. To calculate the increase in boiling point, we need to find the molality of the solution. First, we find the number of moles of table salt (NaCl) by dividing the mass by the molar mass: 25 g / 58.44 g/mol = 0.4288 mol. Then, we find the molality by dividing the moles by the mass of the solvent (water) in kg: 0.4288 mol / 0.25 kg = 1.715 molal. Finally, we use the molality and the molal boiling point elevation constant for water to calculate the increase in boiling point: 1.715 molal * 0.52 °C/molal = 0.8928 °C.