If 75.0 grams of NaCl are added to 1.00 kg of water resulting in 1.00 L of solution, which of the following would be true? (options in notes)

Question

boiling point would increase

freezing point would increase

vapor pressure would increase

concentration = 1.30 M

boiling point would decrease

freezing point would decrease

vapor pressure would decrease

concentration = 1.30 m

boiling point would not change

freezing point would not change

vapor pressure would not change

concentration = 7.50% (m/v)

Answer 1

When a solute is added to a pure material that is dissolves in, it will increase the boiling point and decrease the freezing point (In a sense the mixed liquid phase is favored energetically over the formation of gas and solid, both separating processes)

The vapor pressure of the liquid goes in the opposite direction of the boiling point, i.e. a high vapor pressure is for a more volatile substance with a lower T_BP)

You have to actually calculate the molarity = 75 g/(58.44 g/mole) all over 1 liter

That should get you to the right answer.