UMass_F03_FinalExamKey

UMass_F03_FinalExamKey - Page 1 of 12 Name Chem 111 10:10a...

This preview shows pages 1–3. Sign up to view the full content.

Page 1 of 12 Name: _______________________________ Chem 111 10:10a section Final Exam This exam is composed of 50 questions. Go initially through the exam and answer the questions you can answer quickly . Then go back and try the ones that are more challenging to you and/or that require calculations. Periodic table, solubility rules, and valuable constants are on the last page of the exam. Feel free to tear it off. As discussed on the course syllabus, honesty and integrity are absolute essentials for this class. In fairness to others, dishonest behavior will be dealt with to the full extent of University regulations. 1. The average molecular speed in a sample of N 2 gas is 478 m/s at 303 K. The average molecular speed in a sample of CO 2 gas at the same temperature is: 1) 304 m s -1 2) 381 m s -1 3) 478 m s -1 4) 326 m s -1 5) 600 m s -1 (2) Same temperature means same kinetic energy, so (OWL 12-6d) KE = 1 2 m N 2 u N 2 2 = 1 2 m CO 2 u CO 2 2 u CO 2 2 = m N 2 m CO 2 u N 2 2 = 2 x 14.01 g mol 1 ( ) 12.01 g mol 1 ( ) + 2 x 16.00 g mol 1 ( ) 478 m s 1 ( ) 2 = 145500 m s 1 ( ) 2 = 381 m s 1 ( ) 2 2. A 1.28 mol sample of Ar gas is confined in a 31.5 liter container at 26.5 °C. If 1.28 mol of F 2 gas is added while doubling the volume and keeping the temperature constant, the average kinetic energy per molecule will: 1) decrease 2) remain the same 3) increase 4) not enough information 5) I don’t have a clue (2) Temperature determines average kinetic energy Chapter 12 3. A sample of Cl 2 gas is confined in a 2.0 liter container at 50 °C. Then 2.5 mol of He is added, holding both the volume and temperature constant. The pressure will increase because: 1) As the number of molecule-wall collisions increases, the force per collision increases. 2) With more molecules per unit volume, the molecules hit the walls of the container more often. 3) With more molecules in the container, the molecules have higher average speeds. 4) With higher average speeds, on average the molecules hit the walls of the container with more force. 5) None of the Above (2) Chapter 12

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Page 2 of 12 Name: _______________________________ 4. A 1.96 mol sample of CO 2 gas is confined in a 49.1 liter container at 32.3 °C. If the temperature of the gas sample is increased to 55.0 °C, holding the volume constant, the pressure will increase because: 1) With higher average speeds, on average the molecules hit the walls of the container with more force. 2) With lower average speeds, the molecules hit the walls of the container less often. 3) As the average speed increases, the number of molecule-wall collisions decreases. 4) None of the above (1) Chapter 12 5. In our bodies, sugar is broken down with oxygen to produce water and carbon dioxide. How many moles of glucose (C 6 H 12 O 6 ) are required to react completely with 42.8 L of oxygen gas (O 2 ) according to the following reaction at 0 ° C and 1 atm pressure? Note that the reaction may need balancing.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern