Reference no: EM131135747

1. Which of the following is an application of osmotic pressure?

salting meats for preservation
mixing water and ethylene glycol in antifreeze
pressurizing beverages with carbon dioxide
salting icy roads
using a pressure cooker to increase the boiling point of water

2. The Henry's law constant for O₂ in water at 25 °C is 1.66 x 10^-6 M/mm Hg. What partial pressure of O₂ is necessary to achieve an equilibrium concentration of 0.150 M O₂?

2.49 x 10^-7 mm Hg
6.23 x 10^-6 mm Hg
1.11 x 10^-5 mm Hg
9.04 x 10⁴ mm Hg
4.02 x 10⁶ mm Hg

3. An organic substance has an enthalpy of vaporization of 29.0 kJ/mol. The compound has a vapor pressure of 524 mm Hg at 25 °C. At what temperature is the vapor pressure equal to 115 mm Hg?

-17 °C
-9 °C
9 °C
25 °C

4. What is the dominant intermolecular force or bond that must be overcome in converting CO₂ from a liquid to a gas?

London dispersion force
hydrogen bonding
dipole-dipole force
covalent bonding

5. The lattice energy of KF is -821 kJ/mol. This energy corresponds to which reaction below?

K(s) + 1/2F₂ → KF(s)
K(g) + F(g) → KF(s)
K(g) + F(g) → KF(s)
K+(g) + F - (g) → KF(s)

6. What is the mole fraction of 1.98 m Fe(NO₃)₃(aq)? The molar mass of Fe(NO₃)₃ is 241.9 g/mol and the molar mass of water is 18.02 g/mol.

0.0345
0.0641
0.324
0.479
0.863

7. Which of the following statements are CORRECT?

1. Solubility is the concentration of solute in equilibrium with undissolved solute in a saturated solution.
2. If two liquids mix to an appreciable extent to form a solution, they are immiscible.
3. If two liquids mix completely in any proportion to form a solution, the resulting solution is supersaturated.

1 only
2 only
3 only
1 and 2
2 and 3

8. Which of the following compounds is expected to have the strongest ionic bonds?

RbI
RbF
LiF
CsBr

9. What is the mole fraction of MgCl₂ in a solution that is 11.04% by mass MgCl2(aq)? The molar mass of MgCl₂ is 95.21 g/mol.

0.02295
0.02349
0.1104
0.1160
1.303

10. What mass of Cu(NO₃)₂ must be added to 1.00 kg H₂O to prepare 97 ppm Cu²⁺(aq)?

3.3 x 10^-4 g
5.2 x 10^-4 g
9.7 x 10^-3 g
0.033 g
0.29 g

11. Which of the following properties of water can be attributed to hydrogen bonding?

1. high heat of vaporization
2. high surface tension
3. higher density of liquid versus solid

1 only
2 only
3 only
1, 2, and 3

12. Ideally, colligative properties depend only on the

concentration of solute particles in a solution.
identity of the solute particles in a solution.
color of a solution.
hydrated radii of the molecules or ions dissolved in a solution.
partial pressure of the gases above the surface of a solution.

13. The specific heat capacity of silver is 0.235 J/g K. Its melting point is 962 C and its enthalpy of fusion is 11.3 kJ/mol. What quantity of heat in joules is required to change 5.00 g of silver from a solid at 25 C to a liquid at 962 C?

2,300 joules
345 joules
1,620 joules
902 joules

14. What mass of NaCl must be dissolved in 65.0 grams of water to lower the freezing point by 7.50 °C? The freezing point depression constant, Kfp, for water is -1.86 °C/m.

0.140 g
15.3 g
4.55 g
8.19 g
15.3 g

15. Which of the following ions will have the lowest enthalpy of hydration?

Na⁺
Mg²⁺
K⁺
Ca²⁺

16. To prepare 1.000 kg of 5.5% by mass KCl(aq), one may dissolve

994.5 g KCl in 5.5 g of water.
5.5 g KCl in 994.5 g of water.
5.5 g KCl in 1000.0 g of water.
55 g KCl in 945 g of water.
55.0 g KCl in 1000.0 g of water.

17. If the concentration of potassium chloride in water is 113 ppm, what is the molarity of potassium chloride in water? The molar mass of KCl is 74.55 g/mol. Assume the density of the solution is 1.00 g/mL.

1.52 x 10^-9 M
1.19 x 10^-4 M
1.52 x 10^-3 M
8.42 x 10^-3 M
0.660 M

18. At 25 °C, what is the osmotic pressure of 8.65 g urea (CON₂H₄) diluted with water to 1.50 L? (R = 0.08206 L•atm/mol•K)

0.197 atm
2.35 atm
3.52 atm
141 atm
212 atm

19. The heat of formation of KCl(s) is -436.7 kJ/mol and the heat of formation of KCl(aq, 1 m) is -419.5 kJ/mol. Determine the heat of solution of KCl.

-856.2 kJ/mol
-17.2 kJ/mol
+1.041 kJ/mol
+17.2 kJ/mol
+856.2 kJ/mol

20. What is the definition of molality?

moles of solute per liter of solution
grams of solute per kg of solution
milligrams of solute per liter of solution
moles of solute per liter of solvent
moles of solute per kg of solvent

21. What is the freezing point of a solution containing 4.78 grams naphthalene (molar mass = 128.2 g/mol) dissolved in 32.0 grams paradichlorobenzene? The freezing point of pure paradichlorobenzene is 53.0 °C and the freezing point depression constant, Kfp, is -7.10 °C/m.

-1.63 °C
44.7 °C
46.9 °C
51.9 °C
52.1 °C

22. The osmotic pressure of blood is 7.65 atm at 37 °C. What mass of glucose (C6H12O6, molar mass = 180.2 g/mol) is needed to prepare 5.00 L of solution for intravenous injection? The osmotic pressure of the glucose solution must equal the osmotic pressure of blood. (R = 0.08206 L•atm/mol•K)

1.50 g
54.2 g
126 g
271 g
2270 g

23. The Henry's law constant for N₂ in water at 37 °C is 8.2 x 10^-7 M/mm Hg. What is the equilibrium concentration of N₂ in water when the partial pressure of N₂ is 634 mm Hg?

1.3 x 10^-9 M
5.2 x 10^-4 M
1.9 x 10^-2 M
1.9 x 10³ M
7.7 x 10⁸ M

24. Which substance will most likely NOT quantitatively follow Henry's law when dissolved in water?

He
O₂
CH₄
N₂
NH₃

25. Which of the following compounds is expected to have the strongest ionic bonds?

MgO
KBr
NaI
BaO