View Attempt
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View View Attempt as PDF for free.
More details
- Words: 1,207
- Pages: 7
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
View Attempt 1 of 1 Title:
Exam 1
Started:
September 28, 2009 4:00 PM
Submitted:
September 28, 2009 4:52 PM
Time spent:
00:52:14
Total score: 15/20 = 75%
Total score adjusted by 0.0
Maximum possible score: 20
1. Which type of intermolecular force ("interparticle force") is the most important in CCl4(l)?
Student Response
Correct Answer
1. London Dispersion 2. Dipole-dipole forces 3. Ion-dipole forces 4. Hydrogen bonds 5. Ionic bonds Score:
0/1
2. Which of the following substances would be expected to have the lowest vapor pressure?
Student Response
Correct Answer
1. methane 2. CF4 3. CCl4 4. CBr4 5. CI4 Score:
1/1
3. How much energy in J is needed to convert 13 g of solid ethanol at -150 o C to liquid at -109o C. You might need to know that: mp = -114 o C and bp = 78o C The heat of fusion is 4.6 kJ/mol and the heat of vaporization is 46.0 kJ/mol. Finally, the specific heats of the solid, liquid and gas are, respectively 2.1, 3.2 and 1.8 J/g o C.
1 of 7
11-Oct-09 2:19 AM
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Student Response
Correct Answer
1. 2490 2. 1190 3. 61000 4. 14190 5. 2915 Score:
1/1
4. Which of the following is not indicative of the existence of weak intermolecular forces of attraction in a liquid?
Student Response
Correct Answer
a. a very low boiling point b. a very low vapor pressure c. a very low viscosity d. a very low heat of vaporization e. a very low freezing point Score:
0/1
5. Which of the following statements is true?
Student Response
Correct Answer
a. Ideal colligative properties do not depend on the nature of the solute particles in a given solution. b. The addition of a non-volatile solute to a solvent increases the vapor pressure of the resulting solution. c. The osmotic pressure of a solution is directly proportional to the mole fraction of the solvent. d. Molarity is independent of temperature e. The freezing point depression constant is dependent on the solute present in a solution Score:
1/1
6.
2 of 7
11-Oct-09 2:19 AM
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
What is the strongest form of intermolecular force between solute and solvent in a solution of C4H10(g) in C6H14(l)?
Student Response
Correct Answer
1. ion-dipole 2. dipole-dipole 3. hydrogen bonding 4. dipole-induced dipole 5. dispersion Score:
0/1
7. Which of the following is more soluble in ethanol, CaCO3(s) or NaCl(s). Don't try to type the subscripts, just use letters and numbers.
Student Response
Equals NaCl(s) (100%) Equals NaCl (100%) Equals sodium chloride (100%)
1. NaCl
Score:
Correct Answer
1/1
8. Calculate the molality of an aqueous solution that is 20.1% by mass calcium chloride. You might need to know that the density is 1.20 g/mL.
Student Response
Correct Answer
a. 2.26 b. 2.17 c. 3.33 d. 1.81 e. 2.63 Score:
1/1
9. How many moles of solute particles are present in 5.08 mL of 0.834 M Na2SO4? Use scientific notation with 3 significant figures!!!!
3 of 7
11-Oct-09 2:19 AM
View Attempt
4 of 7
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Answer Score:
Student Response
Correct Answer
1.27E-2
1.27E-2 (1.27 × 10-2)
1/1
10. Which of the following aqueous solutions will have the lowest vapor pressure?
Student Response
Correct Answer
a. 0.100 m K3PO4 b. 0.100 m CaCl2 c. 0.100 m NaCl d. 0.100 m glucose (C6H12O6) e. All have the same molality so all will have the same value. Score:
0/1
11. Calculate the osmotic pressure at 16.7 degrees C of a 0.023 M solution of glucose.
Answer Score:
Student Response
Correct Answer
6.66
0.55
0/1
12. 1.18 grams of an unknown non-electrolytic solute were dissolved in 50.0 g of water (Kfp = 1.86 K/m). If the freezing point of the solution was -0.360 o C, determine the molar mass of the unknown solute.
Student Response
Correct Answer
a. 122 g/mol b. 4.57 g/mol c. 0.12 g/mol d. 88 g/mol e. 219 g/mol Score:
1/1
11-Oct-09 2:19 AM
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
13. H2Z is a nonvolatile, water-soluble substance. When 6.15 x 10-3 mol of H2Z is dissolved in 50.0 g of water (Kfp = 1.86 o C/m), the freezing point of the resulting solution is –0.69 o C. Choose the equation that best describes the dissolution of H2Z. I. H2Z(s) => H2Z(aq) II. H2Z(s) => H+(aq) + HZ-(aq) III. H2Z(s) => 2H+(aq) + Z2-(aq)
Student Response
Correct Answer
a. I only b. II only c. III only d. Equal combination of I and II e. Equal combination of II and III Score:
1/1
14. For the reaction, 2 A(g) + 2 B(g) => C(g) + 3 D(g), the following data were obtained at constant temperature. Experiment
Initial [A], mol/L
Initial [B], mol/L
Initial Rate, M/min
1
0.11
0.15
2.0 x 10-5
2
0.11
0.30
2.0 x 10-5
3
0.22
0.45
4.0 x 10-5
4
0.22
0.60
4.0 x 10-5
Calculate the value of k to 3 significant figures.
Student Response 1. 1.82E-4
Score:
Correct Answer Equals 0.000182 (100%) Equals .000182 (100%) Equals 1.82E-4 (100%)
1/1
15. In a first order decomposition in which the rate constant is 0.0328 sec-1, how long will it take (in minutes) until 0.217 mol/L of the compound is left, if there was 0.881 mol/L at the start? (give answer to 3 sig figs using E notation)?
5 of 7
11-Oct-09 2:19 AM
View Attempt
6 of 7
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Answer Score:
Student Response
Correct Answer
7.12E-1
0.712
1/1
16. The rate law for the reaction 2A => 4B is rate = k[A] with a rate constant of 4.45 sec-1 What is the half-life of the reaction?
Student Response
Correct Answer
1. 2.23 2. 6.42 3. 0.156 4. 0.449 5. Cannot answer without knowing the initial concentration. Score:
1/1
17. The rate law of a particular reaction is found to be, rate = k[A]2[B]. Which of the following statements is FALSE?
Student Response
Correct Answer
a. The reaction is third order overall. b. The units of k could be (L2/mol2 sec) c. Tripling the concentration of A will result in a nine-fold increase in the rate d. The actual value of k will depend on the temperature e. The actual value of k will depend on the concentrations of A and B. Score:
1/1
18. Consider the reaction with the rate law, Rate = k[BrO3-][Br-][H+]2 By what factor does the rate change if the concentration of BrO3- is quadrupled and that of Br- is is decreased by a factor of 2? Just put in the number as a whole number or fraction.
Student Response
Correct Answer
11-Oct-09 2:19 AM
View Attempt
7 of 7
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Equals 2 (100%) Equals 2/1 (100%)
1. 2
Score:
1/1
19. What is the overall reaction order for a reaction with the following rate law? Rate = k[Cl2][H+]2[CO]2
Student Response
Correct Answer
1. First 2. Second 3. Third 4. Fourth 5. Fifth Score:
1/1
20. Consider the equation, 4 NH3 + 5 O2 => 4 NO + 6 H2O. If the water is being produced at a rate of 0.30 M/s, how quickly is the concentration of ammonia decreasing?
Student Response
Correct Answer
a. 0.45 M/s b. 0.20 M/s c. 0.30 M/S d. -0.20 M/s e. -0.45 M/s Score:
1/1
Done
11-Oct-09 2:19 AM
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
View Attempt 1 of 1 Title:
Exam 1
Started:
September 28, 2009 4:00 PM
Submitted:
September 28, 2009 4:52 PM
Time spent:
00:52:14
Total score: 15/20 = 75%
Total score adjusted by 0.0
Maximum possible score: 20
1. Which type of intermolecular force ("interparticle force") is the most important in CCl4(l)?
Student Response
Correct Answer
1. London Dispersion 2. Dipole-dipole forces 3. Ion-dipole forces 4. Hydrogen bonds 5. Ionic bonds Score:
0/1
2. Which of the following substances would be expected to have the lowest vapor pressure?
Student Response
Correct Answer
1. methane 2. CF4 3. CCl4 4. CBr4 5. CI4 Score:
1/1
3. How much energy in J is needed to convert 13 g of solid ethanol at -150 o C to liquid at -109o C. You might need to know that: mp = -114 o C and bp = 78o C The heat of fusion is 4.6 kJ/mol and the heat of vaporization is 46.0 kJ/mol. Finally, the specific heats of the solid, liquid and gas are, respectively 2.1, 3.2 and 1.8 J/g o C.
1 of 7
11-Oct-09 2:19 AM
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Student Response
Correct Answer
1. 2490 2. 1190 3. 61000 4. 14190 5. 2915 Score:
1/1
4. Which of the following is not indicative of the existence of weak intermolecular forces of attraction in a liquid?
Student Response
Correct Answer
a. a very low boiling point b. a very low vapor pressure c. a very low viscosity d. a very low heat of vaporization e. a very low freezing point Score:
0/1
5. Which of the following statements is true?
Student Response
Correct Answer
a. Ideal colligative properties do not depend on the nature of the solute particles in a given solution. b. The addition of a non-volatile solute to a solvent increases the vapor pressure of the resulting solution. c. The osmotic pressure of a solution is directly proportional to the mole fraction of the solvent. d. Molarity is independent of temperature e. The freezing point depression constant is dependent on the solute present in a solution Score:
1/1
6.
2 of 7
11-Oct-09 2:19 AM
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
What is the strongest form of intermolecular force between solute and solvent in a solution of C4H10(g) in C6H14(l)?
Student Response
Correct Answer
1. ion-dipole 2. dipole-dipole 3. hydrogen bonding 4. dipole-induced dipole 5. dispersion Score:
0/1
7. Which of the following is more soluble in ethanol, CaCO3(s) or NaCl(s). Don't try to type the subscripts, just use letters and numbers.
Student Response
Equals NaCl(s) (100%) Equals NaCl (100%) Equals sodium chloride (100%)
1. NaCl
Score:
Correct Answer
1/1
8. Calculate the molality of an aqueous solution that is 20.1% by mass calcium chloride. You might need to know that the density is 1.20 g/mL.
Student Response
Correct Answer
a. 2.26 b. 2.17 c. 3.33 d. 1.81 e. 2.63 Score:
1/1
9. How many moles of solute particles are present in 5.08 mL of 0.834 M Na2SO4? Use scientific notation with 3 significant figures!!!!
3 of 7
11-Oct-09 2:19 AM
View Attempt
4 of 7
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Answer Score:
Student Response
Correct Answer
1.27E-2
1.27E-2 (1.27 × 10-2)
1/1
10. Which of the following aqueous solutions will have the lowest vapor pressure?
Student Response
Correct Answer
a. 0.100 m K3PO4 b. 0.100 m CaCl2 c. 0.100 m NaCl d. 0.100 m glucose (C6H12O6) e. All have the same molality so all will have the same value. Score:
0/1
11. Calculate the osmotic pressure at 16.7 degrees C of a 0.023 M solution of glucose.
Answer Score:
Student Response
Correct Answer
6.66
0.55
0/1
12. 1.18 grams of an unknown non-electrolytic solute were dissolved in 50.0 g of water (Kfp = 1.86 K/m). If the freezing point of the solution was -0.360 o C, determine the molar mass of the unknown solute.
Student Response
Correct Answer
a. 122 g/mol b. 4.57 g/mol c. 0.12 g/mol d. 88 g/mol e. 219 g/mol Score:
1/1
11-Oct-09 2:19 AM
View Attempt
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
13. H2Z is a nonvolatile, water-soluble substance. When 6.15 x 10-3 mol of H2Z is dissolved in 50.0 g of water (Kfp = 1.86 o C/m), the freezing point of the resulting solution is –0.69 o C. Choose the equation that best describes the dissolution of H2Z. I. H2Z(s) => H2Z(aq) II. H2Z(s) => H+(aq) + HZ-(aq) III. H2Z(s) => 2H+(aq) + Z2-(aq)
Student Response
Correct Answer
a. I only b. II only c. III only d. Equal combination of I and II e. Equal combination of II and III Score:
1/1
14. For the reaction, 2 A(g) + 2 B(g) => C(g) + 3 D(g), the following data were obtained at constant temperature. Experiment
Initial [A], mol/L
Initial [B], mol/L
Initial Rate, M/min
1
0.11
0.15
2.0 x 10-5
2
0.11
0.30
2.0 x 10-5
3
0.22
0.45
4.0 x 10-5
4
0.22
0.60
4.0 x 10-5
Calculate the value of k to 3 significant figures.
Student Response 1. 1.82E-4
Score:
Correct Answer Equals 0.000182 (100%) Equals .000182 (100%) Equals 1.82E-4 (100%)
1/1
15. In a first order decomposition in which the rate constant is 0.0328 sec-1, how long will it take (in minutes) until 0.217 mol/L of the compound is left, if there was 0.881 mol/L at the start? (give answer to 3 sig figs using E notation)?
5 of 7
11-Oct-09 2:19 AM
View Attempt
6 of 7
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Answer Score:
Student Response
Correct Answer
7.12E-1
0.712
1/1
16. The rate law for the reaction 2A => 4B is rate = k[A] with a rate constant of 4.45 sec-1 What is the half-life of the reaction?
Student Response
Correct Answer
1. 2.23 2. 6.42 3. 0.156 4. 0.449 5. Cannot answer without knowing the initial concentration. Score:
1/1
17. The rate law of a particular reaction is found to be, rate = k[A]2[B]. Which of the following statements is FALSE?
Student Response
Correct Answer
a. The reaction is third order overall. b. The units of k could be (L2/mol2 sec) c. Tripling the concentration of A will result in a nine-fold increase in the rate d. The actual value of k will depend on the temperature e. The actual value of k will depend on the concentrations of A and B. Score:
1/1
18. Consider the reaction with the rate law, Rate = k[BrO3-][Br-][H+]2 By what factor does the rate change if the concentration of BrO3- is quadrupled and that of Br- is is decreased by a factor of 2? Just put in the number as a whole number or fraction.
Student Response
Correct Answer
11-Oct-09 2:19 AM
View Attempt
7 of 7
https://scholar.uh.edu/webct/urw/lc305051878.tp305053160/ViewStudent...
Equals 2 (100%) Equals 2/1 (100%)
1. 2
Score:
1/1
19. What is the overall reaction order for a reaction with the following rate law? Rate = k[Cl2][H+]2[CO]2
Student Response
Correct Answer
1. First 2. Second 3. Third 4. Fourth 5. Fifth Score:
1/1
20. Consider the equation, 4 NH3 + 5 O2 => 4 NO + 6 H2O. If the water is being produced at a rate of 0.30 M/s, how quickly is the concentration of ammonia decreasing?
Student Response
Correct Answer
a. 0.45 M/s b. 0.20 M/s c. 0.30 M/S d. -0.20 M/s e. -0.45 M/s Score:
1/1
Done
11-Oct-09 2:19 AM
