Question 1

Which of the following best describes the phenomenon of boiling point elevation?

Accepted Answer

The boiling point of a solvent increases after the addition of a nonvolatile solute.

Question 2

Which equation correctly represents the change in boiling point ($$\Delta T_b) $$due to the addition of a solute?

Accepted Answer

$$\Delta T_b = K_b \cdot m \cdot i$$

Question 3

A solution is prepared by dissolving 13.12 g of aluminum chloride ($$\mathrm{$$AlCl_3$$}) in 615 g of $$water. What is the van't Hoff factor ($$i) $$for $$\mathrm{$$AlCl_3$$}$$?

Accepted Answer

4

Question 4

If a nonvolatile, non-electrolyte solute is dissolved in water, what is the value of the van't Hoff factor ($$i$$)?

Accepted Answer

1

Question 5

A solution is made by dissolving 25.2 g of ethylene glycol ($$\mathrm{C_2H_6O_2}) in 99.5 mL of $$water. Given the density of water is $$1.00\ \mathrm{g/mL}$$, what is the molality ($$m) of $$the solution?

Accepted Answer

$$4.07\ \mathrm{mol/kg}$$

Question 6

Which of the following statements is true regarding the boiling point of a solution compared to the pure solvent?

Accepted Answer

The boiling point of the solution is always higher than that of the pure solvent.

Question 7

Given $$K_b$$ for water is $$0.512\ ^\circ\mathrm{C\cdot kg/mol}$$, what is the boiling point of a solution containing $$1.12\ \mathrm{mol} of a $$nonvolatile solute in $$0.33\ \mathrm{kg} of $$water? Assume $$i=1.$$

Accepted Answer

$$101.74\ ^\circ\mathrm{C}$$

Question 8

A solution is prepared by dissolving glucose in water. If the boiling point of the solution is $$103.15^\circ\mathrm{C}$$, what is the change in boiling point ($$\Delta T_b$$)? (Assume the normal boiling point of water is $$100^\circ\mathrm{C}.)$$

Accepted Answer

$$3.15^\circ\mathrm{C}$$

Question 9

Which of the following would result in the greatest boiling point elevation when dissolved in $$1.0\ \mathrm{kg} of $$water?

Accepted Answer

$$1.0\ \mathrm{mol} of$$ $$\mathrm{$$CaCl_2$$}$$ ($$i=3)$$

Question 10

A student adds $$120\ \mathrm{g} of $$carbon dioxide to $$722\ \mathrm{mL} of $$benzene (density $$1.59\ \mathrm{g/mL}). $$What is the molality of the solution? (Molar mass of $$\mathrm{CO_2$} = 44.0\ \mathrm{g/mol})$$

Accepted Answer

$$2.50\ \mathrm{mol/kg}$$

Question 11

If the boiling point elevation constant ($$K_b) $$for benzene is $$2.53\ ^\circ\mathrm{C\cdot kg/mol}$$, what is the boiling point elevation for a $$2.50\ \mathrm{mol/kg}$$ solution of a nonvolatile, non-electrolyte solute?

Accepted Answer

$$6.33^\circ\mathrm{C}$$

Question 12

Which of the following best explains why the boiling point of a solution increases when a solute is added?

Accepted Answer

The solute decreases the vapor pressure of the solvent, requiring a higher temperature to boil.

Question 13

A $$3.71\ \mathrm{m}$$ aqueous $$\mathrm{$$CaBr_2$$}$$ solution is prepared. If $$K_b$$ for water is $$0.512\ ^\circ\mathrm{C\cdot kg/mol}$$, what is the boiling point elevation? ($$i$$ for $$\mathrm{$$CaBr_2$$} is 3)$$

Accepted Answer

$$5.70^\circ\mathrm{C}$$

Question 14

Which of the following is NOT a factor that affects the boiling point elevation of a solution?

Accepted Answer

The color of the solute

Question 15

A nurse needs to prepare a solution with a specific boiling point for sterilization. If the solution must boil at $$102.0^\circ\mathrm{C}$$, and the solvent is water ($$K_b = 0.512\ ^\circ\mathrm{C\cdot kg/mol}$$), what is the required molality of a nonvolatile, non-electrolyte solute?

Accepted Answer

$$2.00\ \mathrm{mol/kg}$$

Question 16

Which of the following real-life scenarios is an example of boiling point elevation?

Accepted Answer

Adding salt to water to cook pasta, causing the water to boil at a higher temperature.

Boiling Point Elevation in Solutions

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