Chemistry 112A Exam 1 Key PDF

Chemistry 112A FIRST EXAM KEY Professor Bleeke This exam from a previous year consists of questions covering representative topics, but not necessarily all of the subject matter discussed so far this semester. ...

Chemistry 112A FIRST EXAM KEY Professor Bleeke This exam from a previous year consists of questions covering representative topics, but not necessarily all of the subject matter discussed so far this semester.  Student ID # ____________________ FIRST EXAM KEY Please fill in the numbers of your 6- Chemistry 112A digit WUSTL ID: Professor Bleeke 6:30 – 8:00 p.m. Student ID # WRITE YOUR STUDENT ID ON EACH PAGE OF THE EXAM, 9 9 9 9 9 9 INCLUDING THE SCRATCH PAGE. 8 8 8 8 8 8 7 7 7 7 7 7 1.5 HOURS will be allowed for the exam. The examination contains 6 6 6 6 6 6 8 questions on 10 numbered pages, including the last SCRATCH PAGE. 5 5 5 5 5 5 4 4 4 4 4 4 TURN IN THE ENTIRE EXAM (INCLUDING THE SCRATCH PAGE) 3 3 3 3 3 3 WHEN YOU ARE FINISHED! 2 2 2 2 2 7 2 1 1 1 1 1 1 Exam Points Breakdown: 0 0 0 0 0 0 1. (12 pts) 2. (08 pts) 3. (12 pts) 4. (14 pts) 5. (13 pts) 6. (13 pts) 7. (14 pts) 8. (14 pts) Total Points: (100 pts) REGRADE INFORMATION: Read the regrade information section in the general information/FAQs/policies handout and fully review the exam key posted to Canvas (this usually contains more thorough information than that shown on Gradescope). An electronic regrade request form must be completed by the due date. Exam 1 regrade requests must be turned in by 4:00 PM on the due date.  Correct Answers with Reasonable Work Receive Full Credit 2 Student ID # ____________________ 1. (12 Total Points) a) Consider the following balanced chemical reaction: 2 ClO (g) ⇌ Cl (g) + ClO2 (g) 08 The equilibrium constant, K, for this reaction at 385 K is 4.26 × 10−4. Using this information, answer pts the following questions. 1.240 atm of ClO (g) and 0.330 atm of Cl (g) are sealed in a container at 385 K. No ClO2 (g) is present initially. Determine the partial pressures of all three gases, ClO (g), Cl (g) and ClO2 (g) (in atm), after equilibrium is established. Show all work and record your final answers on the lines provided below. Report each answer to at least 3 significant figures. 2 ClO (g) ⇌ Cl (g) + ClO2 (g) I 1.240 atm 0.330 atm 0 atm C −2x +x +x E 1.240 − 2x 0.330 + x x PClO2 × PCl x(0.330 + x) K = 4.26 × 10−4 = 2 = PClO (1.240 − 2x)2 Using MOSA: Assume 2x