You have learned that adding table salt,NaCl (58.4 g/mol,2.16 g/cm³),to water (K_b = 0.52 $\circ$ C/m)increases the temperature at which it boils.You decide to try cooking pasta faster at a higher temperature in boiling salty water.What increase in the boiling point do you expect if you add 1 tablespoon (1 tbsp = 14.8 cm³)of salt to one 8 oz cup of water (237 mL)?

Question

Quizplus · Accepted Answer

Using the formula ΔT = K * m * i where K is the molal boiling point elevation constant (0.52 for water), m is the molality of the solution (calculated by dividing the moles of salt by the mass of water), and i is the van't Hoff factor (2 for NaCl), we can calculate the expected increase in boiling point:
moles of NaCl = 14.8 cm / 58.4 g/mol = 0.253 moles
mass of water = 237 mL = 237 g
molality = 0.253 / 0.237 = 1.07 mol/kg
ΔT = 0.52 * 1.07 * 2 = 1.12 C
Converting to Fahrenheit, we get 2.02 F, which rounds up to 2.4 F. Therefore, the best answer is B, an increase in boiling point of 2.4F1F1F1S1F1F1F10C.

You Have Learned That Adding Table Salt,NaCl (58 ∘\circ∘ C/m)increases the Temperature at Which It Boils

You Have Learned That Adding Table Salt,NaCl (58 $\circ$ C/m)increases the Temperature at Which It Boils