ExamView - Exam 2-A With answer sheet.pdf

6 Pages
164 Views

Department
Chemistry
Course Code
CHEM 112
Professor
Chris Mc Daniel

This preview shows pages 1 and half of page 2. Sign up to view the full 6 pages of the document.
Description
CHEM-112-01 Spring 2012 Name: ________________________ Class: ___________________ Date: __________ ID: A 1. Record your name and ID number on the scantron form. 2. Record the test ID letter in the top right box of the scantron form. 3. Record all of your answers on the scantron form. DO NOT wait until the end to do this ! 4. Remain seated until the period is over. 5. Pass the scantron form to the center. 6. Take your exam with you. You have 50 minutes. GOOD LUCK ! Exam 2 Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 1. What is the ID letter of your exam? Record this for question 1. a. A d. D b. B e. E c. C ____ 2. If 355 g of ethanol (C2H 5H) is added to 645 g of water, what is the molality of the ethanol? a. 0.550 m b. 7.71 m c. 11.9 m d. 21.7 m e. 55.0 m ____ 3. The heat of formation of NaCl(s) is –411.1 kJ/mol and the heat of formation of NaCl(aq, 1 m) is –407.3 kJ/mol. Determine the heat of solution of NaCl. Will the solution temperature increase or decrease when NaCl is dissolved in water? a. –3.8 kJ/mol; increase b. +3.8 kJ/mol; increase c. +3.8 kJ/mol; decrease d. +818.4 kJ/mol; increase e. –818.4 kJ/mol; decrease ____ 4. Which action(s) will increase the equilibrium concentration of a non-reacting gas in water? 1. decreasing the temperature of the water 2. increasing the volume of water 3. decreasing the pressure of the gas above the liquid a. 1 only b. 2 only c. 3 only d. 1 and 3 e. 1, 2, and 3 1 Name: ________________________ ID: A ____ 5.Arrang PeH 3, AsH 3 and SbH i3 order from lowest to highest boiling point. a. SbH 3< AsH <3PH 3 b. PH 3 AsH < S3H 3 c. PH 3 SbH < A3H 3 d. AsH <3SbH < P3 3 e. SbH < PH < AsH 3 3 3 ____ 6. What is the freezing point of a solution containing 3.10 grams benzene (molar mass = 78.11 g/mol) dissolved in 32.0 grams paradichlorobenzene? The freezing point of pure paradichlorobenzene is 53.0 C and the freezing point depression constant, K fp is –7.10 C/m. a. 44.2 C b. 51.8 C c. 52.3 C d. 54.2 C e. 61.8 C ____ 7. What is the H O 3oncentration of an aqueous solution with a pH of 8.77? –9 a. 1.7  10 M b. 5.9  10 M6 –4 c. 1.6  10 M d. 5.23 M 8 e. 5.9  10 M ____ 8. As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PBr 3, SO 2 I2, and CO ? 2 a. PBr 3 only b. PBr and SO 3 2 c. SO 2nd CO 2 d. I and CO 2 2 e. PBr 3 SO ,2and I 2 ____ 9. Ethanol has an enthalpy of vaporization of 42.3 kJ/mol. The compound has a vapor pressure of 1.00 atm at 78.3 C. At what temperature is the vapor pressure equal to 0.500 atm? (R = 8.314 J/Kmol) a. –96.2 C b. 7.19 C c. 36.0 C d. 62.2 C e. 281 C ____ 10. Normal boiling point is defined as a. the temperature at which the vapor pressure of a liquid equals 1 atm. b. the pressure at which any liquid boils at 373.15 K. c. the temperature at which water always boils. d. the pressure of a gas when its temperature reaches 273.15 K. e. the temperature at which the enthalpy of vaporization equals 100.0 kJ/mol. 2 Name: ________________________ ID: A ____ 11. What is the pH of 0.25 M aqueous acetic acid? (K of CH CO a = 1.8 3 102) –5 a. 0.60 b. 2.67 c. 4.74 d. 5.35 e. 9.26 ____ 12. Which of the following statements is/are CORRECT? 1. If the intermolecular forces in a liquid decrease, the normal boiling point of the liquid decreases. 2. If the surface area of a liquid increases, the equilibrium vapor pressure of the liquid increases. 3. If the temperature of a liquid decreases, the equilibrium vapor pressure increases. a. 1 only b. 2 only c. 3 only d. 1 and 2 e. 1, 2, and 3 –4 –14 ____ 13. What is the pH of 4.4  10 M KOH(aq) at 25 C? (K = 1.0  10 w ) a. –3.36 b. 3.36 c. 6.27 d. 7.73 e. 10.64 ____ 14. Which equation depicts hydrocyanic acid, HCN, behaving as a Brønsted-Lowry acid in water? a. HCN(aq) + OH (aq)– OCN (aq) + H (g2 + + b. HCN(aq) + H 3O (aq) H 2N (aq) + H O(™2 c. HCN(aq) + H 2O(™) CN (aq) + H O 3aq) – + d. CN (aq) + H 3 (aq) HCN(aq) + H O(™2 e. CN –(aq) + H 2(™) OCN (aq) + H (s)2 ____ 15. Ideally, colligative properties depend only on the a. concentration of solute particles in a solution. b. molar masses of the solute particles in a solution. c. density of a solution. d. hydrated radii of the molecules or ions dissolved in a solution. e. partial pressure of the gases above the surface of a solution. 3 Name: ________________________ ID: A ____ 16. At its boiling point of –34.0 C, 6.33 kJ of heat is required to vap
More Less
Unlock Document

Only pages 1 and half of page 2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit