Q: A 68.0 kg person has about 0.20% sodium by mass in their body and 4.8 liters of blood. What is the molar concentration of sodium ions in their blood? (Molar mass of Na = 23.0 g/mol)

$$[Na^+] = \frac{0.002 \times 68.0}{4.8} \div 23.0$$

Q: A bottle of soda is sealed under a pressure of 2.05 atm of CO2. Using Henry’s Law ($$C_{CO_2$} = k_{CO_2$} \cdot P_{CO_2$}$$, $$k_{CO_2$} = 0.031 \text{ mol/L·atm}$$), how many grams of CO2 are dissolved in a 2.00-liter bottle?

$$2.00 \times 0.031 \times 2.05 \times 44.0$$

Q: What is the osmotic pressure required to prevent the flow of pure water into seawater with a total ionic concentration of 1.13 mol/L at 25°C? ($$R = 0.0821 \text{ L·atm·mol}^{-1}\text{·K}^{-1})$$

$$\Pi = 1.13 \times 0.0821 \times 298$$

Q: A 50% ethylene glycol and 50% water solution by volume is prepared. If the density of ethylene glycol is 1.113 g/mL, what is the molal concentration of ethylene glycol in the solution? (Molar mass C2H6O2 = 62.07 g/mol)

$$m = \frac{50 \times 1.113 / 62.07}{50 / 1000}$$

Question 1

Which of the following best describes a solution that contains 4000 grams of sugar dissolved in 1L of water at 90°C, then cooled to 50°C?

Accepted Answer

Supersaturated

Question 2

A 68.0 kg person has about 0.20% sodium by mass in their body and 4.8 liters of blood. What is the molar concentration of sodium ions in their blood? (Molar mass of Na = 23.0 g/mol)

Accepted Answer

$$[Na^+] = \frac{0.002 	imes 68.0}{4.8} \div 23.0$$

Question 3

Which intermolecular force is primarily responsible for the miscibility of ethylene glycol and water?

Accepted Answer

Hydrogen bonding

Question 4

A 30.0% H2SO4 solution by mass has a density of 1.26 g/mL. What is the molality of H2SO4 in this solution? (Molar mass H2SO4 = 98.1 g/mol)

Accepted Answer

$$m = \frac{30.0}{98.1} \div \frac{70.0}{1000}$$

Question 5

Which of the following solutions will have the lowest freezing point? (Assume ideal behavior and equal molality)

Accepted Answer

0.02 m MgCl2

Question 6

What is the van’t Hoff factor ($$i) $$for NaCl in aqueous solution?

Accepted Answer

$$i = 2$$

Question 7

A bottle of soda is sealed under a pressure of 2.05 atm of CO2. Using Henry’s Law ($$C_{CO_2$} = k_{CO_2$} \cdot P_{CO_2$}$$, $$k_{CO_2$} = 0.031 	ext{ mol/L·atm}$$), how many grams of CO2 are dissolved in a 2.00-liter bottle?

Accepted Answer

$$2.00 	imes 0.031 	imes 2.05 	imes 44.0$$

Question 8

Which of the following best explains why gases dissolve less well in warm water, according to kinetic molecular theory?

Accepted Answer

Gas molecules escape more easily from solution at higher temperatures

Question 9

What is the osmotic pressure required to prevent the flow of pure water into seawater with a total ionic concentration of 1.13 mol/L at 25°C? ($$R = 0.0821 	ext{ L·atm·mol}^{-1}	ext{·K}^{-1})$$

Accepted Answer

$$\Pi = 1.13 	imes 0.0821 	imes 298$$

Question 10

Which of the following best describes the effect of a hypertonic solution on a cell?

Accepted Answer

The cell shrivels as water flows out

Question 11

Which equation correctly describes the freezing point depression for a solution?

Accepted Answer

$$\Delta T_f = i \cdot K_f \cdot m$$

Question 12

A 394-gram sample of soda contains 39.0 grams of sugar (C12H22O11). What is the mole fraction of sugar in this mixture? (Molar mass C12H22O11 = 342.3 g/mol)

Accepted Answer

$$\chi = \frac{39.0/342.3}{(39.0/342.3)+(355/18.0)}$$

Question 13

Which of the following aqueous solutions has the lowest boiling point? (Assume equal molality and ideal behavior)

Accepted Answer

0.10 m C12H22O11, sucrose

Question 14

What is the molal concentration of sucrose in water if the boiling temperature of the solution is 113°C? (Kb for water = 0.512 °C/m, i = 1)

Accepted Answer

$$m = \frac{113 - 100}{0.512}$$

Question 15

Which intermolecular force is strongest in the formation of an aqueous solution of NaCl?

Accepted Answer

Solvent-solute (ion-dipole)

Question 16

A 50% ethylene glycol and 50% water solution by volume is prepared. If the density of ethylene glycol is 1.113 g/mL, what is the molal concentration of ethylene glycol in the solution? (Molar mass C2H6O2 = 62.07 g/mol)

Accepted Answer

$$m = \frac{50 	imes 1.113 / 62.07}{50 / 1000}$$

Question 17

Which of the following best describes the effect of adding a nonvolatile solute to a solvent?

Accepted Answer

Decreases the vapor pressure of the solvent

Question 18

What is the correct formula for calculating molarity?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{total volume of solution (L)}}$$

Chapter 13: Solutions and Colligative Properties – Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드