NAME ______________________________________________ © Keeney-Kennicutt, 2010 A1 CHEMISTRY 101 SPRING 2010 EXAM 2 FORM A SECTION 502 DR. KEENEY-KENNICUTT Directions: (1) Put your name on PART 1 and your name and signature on PART 2 of the exam where indicated. (2) Sign the Aggie Code on PART 2 of this exam. (3) Each multiple choice question is actually 2 questions on your scanning sheet. If you are sure of an answer, put the same answer down for both questions for 5 pts. If you cannot decide between two answers, put your BEST answer down for the ODD/FIRST question for 3 pts and your SECOND BEST answer down for the EVEN/SECOND question for 2 pts. If there is an ambiguous multiple choice question, use the last page to explain your answer. (4) Do NOT write on the envelope. (5) When finished, put everything in the envelope and wait to be excused. At the table, take everything out of the envelope. You can pick up the multiple choice part with the answers outside my office after 2:30pm. (6) There are a total of 34 questions (18 actual questions). PART 1 1&2. In Bronsted-Lowry Theory of acids and bases, an acid is defined as: (a) a proton donor (b) a hydroxide donor (c) an electron-pair acceptor (d) a water-former (e) a proton acceptor 3&4. Determine the oxidation number of bromine in the perbromate ion, BrO4−. (a) +2 (b) +4 (c) +6 (d) +7 (e) +8 5&6. Assign oxidation numbers to each element in this unbalanced reaction. The oxidation agent is: P4 + NO → P4O6 + N2 (a) P4 (b) NO (c) P4O6 (d) N2 (e) this is not a redox reaction 7&8. Which statement is FALSE? (a) Energy is the capacity to do work. (b) An exothermic reaction releases heat. (e) When two objects come into contact, they will in time be at the same temperature. (d) A joule is a unit of energy. (c) Heat flows from a cold object to a hot one.© Keeney-Kennicutt, 2010 A2 9&10. Here is a particle view of a substance in water. Pick the compound that is represented by this particle view. = cation or H = anion (a) NaCl (b) NaOH (c) AgOH (d) HF (e) LiCH3COO 11&12. Balance the equation with the SMALLEST WHOLE NUMBER COEFFICIENTS possible. Choose the number that is the SUM of the coefficients in the balanced equation. Don’t forget coefficients of one. Na2SO3 + HCl Æ NaCl + H2O + SO2 (a) 5 (b) 7 (c) 9 (d) 12 (e) 15 13&14. Consider this acid-base net ionic equation: CH3COOH(aq) + OH–(aq) Æ CH3COO–(aq) + H2O(l) Which of the following statements is TRUE? (a) The acid is a strong acid. (b) The base is insoluble. (c) The spectator ion could have been a NO3– ion. (d) The salt is a weak electrolyte. (e) The spectator ion could have been a Na+ ion.© Keeney-Kennicutt, 2010 A3 15&16. Consider this graph representing A →← B. Which is the FALSE statement? (a) A and B reach equilibrium after 15 minutes. (b) The reaction is reactant-favored. (c) After about 15 minutes, the concentrations of A and B seem to be about constant. (d) After about 15 minutes, A is becoming B just as fast as B is converting to A. (e) Even after 15 minutes, the system is very dynamic. 17&18. The pH of a 0.0177 M solution of HClO3 is (a) 4.03 (b) 1.04 (c) 1.75 (d) 1.00 (e) 2.15 19&20. How many moles of NH3 will be produced when 8.94 moles of H2O are also produced according to the following equation? Ce2O3 + 6 NH4Cl Æ 2 CeCl2 + 3 H2O + 6 NH3 (a) 4.47 mol (b) 13.4 mol (c) 6.00 mol (d) 17.9 mol (e) 2.24 mol© Keeney-Kennicutt, 2010 A4 21&22. How many grams of patassium chloride are in 775 mL of a solution which is 35.5% KCl by weight and has a density of 1.28 g/mL? (a) 215 g (b) 275 g (c) 352 g (d) 640 g (e) 972 g 23&24. Carbon tetrachloride, a valuable commercial solvent, can be produced by the gas phase reaction of methane with chlorine gas. CH4 + 4 Cl2 Æ CCl4 + 4 HCl Assuming this process is 64% efficient, how many kilograms of chlorine are required for the production of 15 kg of CCl4, assuming excess CH4? (a) 43 kg (b) 18 kg (c) 67 kg (d) 83 kg (e) 96 kg© Keeney-Kennicutt, 2010 A5© Keeney-Kennicutt, 2010 A6 25&26. Consider the reaction: 2 KCrO2 + 3 H2O2 + 2 KOH → 2 K2CrO4 + 4 H2O If 20.0 g of each reactant were used for this reaction, the limiting reactant would be: (a) KCrO2 (b) H2O2 (c) KOH (d) K2CrO4 (e) H2O 27&28. How many milliliters of a 1.40 M NaOH solution are required to make 250. mL of 0.100 M NaOH solution? (a) 14.7 mL (b) 3500 mL (c) 17.9 mL (d) 35.0 mL (e) 25.0 mL© Keeney-Kennicutt, 2010 A7 29&30. If 6.00 g of HBr was dissolved in enough water to give a pH of 1.78, what was the volume of the solution? (a) 4.47 L (b) 1.30 L (c) 2.59 L (d) 5.95 L (e) 3.22 L 31&32. A 2.00 g sample of calcite ore containing CaCO3 reacted totally with 15.22 mL of 2.30 M hydrochloric acid until no more carbon dioxide gas was evolved according to: CaCO3 + HCl Æ H2O + CaCl2 + CO2 (UNBALANCED) What percentage of the sample was CaCO3? (a) 96.2% (b) 71.9% (c) 63.1% (d) 87.6% (e) 43.8%© Keeney-Kennicutt, 2010 A8 CHEMISTRY 101 EXAM 2 Form A SPRING 2010 Section 502 NAME PLEASE BLOCK PRINT PART 2 Please read and sign: “On my honor, as an Aggie, I have neither given nor received unauthorized aid on this exam.” _______________________________________________ 33. Consider the precipitation reaction between aqueous solutions of sodium phosphate and calcium nitrate. If you have problems with the nomenclature, make something up and go with that to get partial credit. (4 pts) (a) What is the balanced formula unit equation? Include the phase for every compound. (2 pts) (c) What is/are the spectator ion/s, if any? (2 pts) (d) What is the net ionic equation? Include the charge for every ion.© Keeney-Kennicutt, 2010 A9 OVER ⇒© Keeney-Kennicutt, 2010 A10 34. Consider this reaction: S + O2 → SO3 . (2 pts) (a) Balance the equation. (3 pts) (b) If you had 6 moles of S and 3 moles of O2, draw the particle view that would represent the final situation. Let = S and = O Initial system
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