(1) Fill in this cover sheet. (1) On the Answer Sheet under Exam Information: - Test Version bubble in your version, which is located next to your signed name on this cover sheet (if not filled in, your paper will not be graded!) (2) On the Answer Sheet under Student Information: - STUDENT ID write your 8 digit UB person number vertically & bubble in the numbers - Integrity Certification  Sign your name stating you will not cheat on this exam - NAME  print your first name, last name and your - UBIT name  from your email (3) Check that you have a complete examination (10 pages – including Formula Sheet and Periodic Table). Print your name on the top of every page of the Examination and hand in ALL pages when you are done. (4) To answer a question: fill in the circle on the bubble sheet that corresponds to the BEST answer. You may use a pencil or a pen (blue or black ink only, and no felt tips). If you decide to change your answer write an “X” over the incorrect answer, fill in the new correct answer and write the letter for the correct answer to the left of the question number. Questions with more than one answer marked and not written as stated above will be graded as incorrect. The only answers accepted are those which appear on the bubble sheet. There are 25 questions, 4 points each (Total possible points = 100) PLEASE READ AND SIGN THE ACADEMIC HONESTY STATEMENT BELOW. I hereby certify that the answers given represent my own unaided work. Signed: ___________________________________________ Test Version: A Printed Name: ______________________________________ Person Number: ___ ___ ___ ___  ___ ___ ___ ___ Day/Time of Recitation: ______________________________ Recitation Code: ___ ___ Name of TA: _______________________________________ CHEM 102/112 Exam #1 March 3rd 2017 (1 hr 30 min)Name: _______________________________________ 2 1. Consider the following pairs of liquids. Which pairs are miscible? I. Benzene, C6H6, and Hexane, C6H14 II. Water and Methanol, CH3OH III. Water and Hexane A) I & II only C) I only E) I, II & III B) II only D) III only 2. What are the ideal van’t Hoff factors for the following compounds? BaF2 C6H12O6 K3PO4 (NH4)2SO4 A) 1, 1, 1, 1 B) 3, 1, 4, 1 C) 3, 1, 4, 3 D) 2, 3, 5, 5 E) None of the above 3. A solution made by dissolving 9.81 g of a nonvolatile nonelectrolyte in 90.0 g of water boiled at 100.37 C and 760.1 mmHg. What is the approximate molecular weight (in g/mol) of the nonelectrolyte substance? A) 240 B) 150 C) 79 D) 61 E) 34 4. At 20. C and 1.00 atm of partial pressure of O2, the solubility of O2 in water is 1.38x103 M. At sea level however, the partial pressure of O2 is 0.21 atm. Calculate the concentration (M) of O2 in water at sea level. A) 1.4x103 B) 6.6x103 C) 2.9x104 D) 0.21 E) None of these answers are correct SubstanceNormal Boiling Point (°C)Kb (°C/m)Normal Freezing Point (°C)Kf (°C/m)Water 100.00 0.51 0.00 1.86Name: _______________________________________ 3 5. (Hw): During the formation of a solution, which step is always an exothermic process? A) Only the separation of solvent particles to accommodate solute particles (Hsolvent). B) The mixing of solute particles and solvent particles with one another (Hmix). C) The overall solution process (HSoln). D) Only the separation of solute particles from one another (Hsolute). E) The separation of solute and solvent particles from one another (Hsolute and Hsolvent). 6. A solution is prepared by dissolving 23.7 g of aspirin, C9H8O4, in 375 g of water. The density of the resulting solution is 1.05 g/mL. What is the molar concentration of aspirin? A) 0.347 B) 0.35 C) 54.7 D) 878 E) 0.063 7. Of the concentration units below, only __________ is temperature dependent. A) mass% B) ppm C) mole fraction D) molarity E) molality 8. What is the osmotic pressure (in atm) of a solution formed by dissolving 25.0 mg of CaCl2, in 250. mL of water at 25 C? A) 7.34 B) 9.01x104 C) 0.0661 D) 0.0220 E) 2.25x104Name: _______________________________________ 4 9. The combustion of ethane (C2H6) is represented by the equation below, in this reaction: 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l) A) the rate of consumption of ethane is seven times faster than the rate of consumption of oxygen. B) the rate of formation of CO2 equals the rate of formation of water. C) water is formed at a rate equal to two-thirds the rate of formation of CO2. D) CO2 is formed twice as fast as ethane is consumed. E) the rate of consumption of oxygen equals the rate of consumption of water. 10. The half-life for a first order reaction is 32 sec. What was the original concentration (M) if after 2.0 minutes the reactant concentration is 0.062 M? A) 0.84 B) 0.069 C) 0.091 D) 0.075 E) 0.13 11. Given that a forward reaction is endothermic with an activation energy of 50 kJ/mol, which of the following statements are correct? I. The reverse reaction has an activation energy equal to 50 kJ/mol. II. The reverse reaction has an activation energy less than 50 kJ/mol. III. The reverse reaction has an activation energy greater than 50 kJ/mol. IV. The reverse reaction will be endothermic. V. The reverse reaction will be exothermic. A) I & IV C) III & IV E) III & V B) II & IV D) II & V 12. Which items correctly complete the following statement? A catalyst can act in a chemical reaction to: I. Increase the equilibrium constant II. Lower the activation energy III. Decrease H for the forward reaction IV. Provide a new path for the reaction A) I & II C) III & IV E) II & IV B) II & III D) I & IIIName: _______________________________________ 5 13. What is the difference between average rate and instantaneous rate? In a given reaction, can these two rates ever have the same numeric value? A) An instantaneous rate is measured at a particular point in time of a reaction, whereas the average rate is measured over a time period. They can have the same numeric value. B) An instantaneous rate is measured at a particular point in time of a reaction, whereas the average rate is measured over a time period. They can’t have the same numeric value. C) An instantaneous rate is measured over a short time period, whereas the average rate is measured over a large time period. They can have the same numeric