Answer to Question #156796 in General Chemistry for Kimberli

Question

1. What occurs when NaCl(s) is added to water?

Boiling point increases and freezing point decrease

(1) The boiling point of the solution increases, and the freezing point of the solution decreases.

(2) The boiling point of the solution increases, and the freezing point of the solution increases.

(3) The boiling point of the solution decreases, and the freezing point of the solution decreases.

(4) The boiling point of the solution decreases, and, the freezing point of the solution increases.

2. Explain, in terms of freezing point, which solute would have a bigger effect on 1000 liters of water: 1.5 mole of KCl or 2 moles of sugar (C​6H​ ​12O​ ​6)​

1.5 KCl - 3 mol total ions

3. Compared to pure water, an aqueous solution of calcium chloride has a

(1) higher boiling point and higher freezing point

(2) higher boiling point and lower freezing point

(3) lower boiling point and higher freezing point

(4) lower boiling point and lower freezing point

4. At standard pressure when NaCl is added to water, the solution will have a

(1) higher freezing point and a lower boiling

point than water

(2) higher freezing point and a higher boiling point than water

(3) lower freezing point and a higher boiling point than water

(4) lower freezing point and a lower boiling point than water

  5. Compared to a 1.0 M aqueous solution of NaCl at 1 atmosphere, a 0​.​5 M aqueous solution of NaCl at 1 atmosphere has a

(1) lower boiling point and a higher freezing point

(2) lower boiling point and a lower freezing point

(3) higher boiling point and a higher freezing point

(4) higher boiling point and a lower freezing point

6. Explain which of the following would be better to use during and after a snowstorm to keep the streets and the sidewalks safe: CaCl​2​ or NaCl

1 mol CaCl2 - 3 mol ions

7. Compared to a 2.0 M aqueous solution of NaCl at 1 atmosphere, a 3.0 M aqueous solution of NaCl at 1 atmosphere has a

(1) lower boiling point and a higher freezing point

(2) lower boiling point and a lower freezing point

(3) higher boiling point and a higher freezing point

(4) higher boiling point and a lower freezing point

8. Which aqueous solution of KI freezes at the ​lowest temperature?

(1) 1 mol of KI in 500. g of water

(2) 2 mol of KI in 500. g of water

(3) 1 mol of KI in 1000. g of water

(4) 2 mol of KI in 1000. g of water

  9. Explain why NYC spreads salt on snow after a snowstorm?

Answer 1

1. Boiling point increases and freezing point decrease.

2. 1.5 KCl - 3 mol total ions.

3. (2) higher boiling point and lower freezing point.

4. (3) lower freezing point and a higher boiling point than water.

5. (4) higher boiling point and a lower freezing point.

6. 1 mol CaCl2 - 3 mol ions.

7. lower boiling point and a higher freezing point.

8. (2) 2 mol of KI in 500. g of water.

9. The salt, via freezing point depression, helps melt the snow and ice and also gives vehicles more traction.