NAME CHEMISTRY 101 SPRING 2009 EXAM 2 FORM A SECTION 501 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 10am. (6) There are a total of 35 questions (19 actual questions) plus one bonus question. PART 1 1&2. Which of the following is NOT a strong acid? (a) HF (b) HClO 3 (c) HBr (d) HNO 3 (e) HI 3&4. Determine the oxidation number of sulfur in the sulfite ion, SO 3 2. (a) 4 (b) 2 (c) +2 (d) +4 (e) +6 5&6. Balance the following reaction. The balanced equation shows that 3.00 moles of NO will produce mole(s) of N 2. P 4 + NO P 4 O 6 + N 2 (a) 1 (b) 1.5 (c) 2 (d) 2.5 (e) 3 7&8. Which statement is TRUE? (a) Water molecules at 25 o C are moving faster than water molecules at 50 o C. (b) To calculate the heat absorbed by water going from 50 o C to 100 o C, one must know the heat of vaporization of water. (c) A substance at a higher temperature always contains more heat than a substance at a lower temperature. (d) An exothermic substance absorbs heat from the surroundings. (e) Water freezing is an exothermic process. Keeney-Kennicutt, 2009 A1
9&10. Given the following formula unit equation, what is(are) the spectator ions? Na 2 CO 3 + 2 AgNO 3 Ag 2 CO 3 + 2 NaNO 3 (a) Na + only (b) CO 2 3 only (c) NO 3 (d) Na + and NO 3 (e) Ag + and CO 3 2 11&12. When chlorous acid is neutralized with lithium hydroxide, the salt produced is: (a) LiCl (b) LiClO (c) LiClO 2 (d) LiClO 3 (e) LiClO 4 13&14. The ph of a 0.00250 M solution of HCl is (a) 1.60 (b) 2.60 (c) 5.99 (d) 1.01 (e) 2.15 15&16. How many ml of 1.60 M NaCl are required to prepare 300. ml of 0.0200 M NaCl? (All the sucker answers are present.) (a) 3.75 ml (b) 9.60 ml (c) 24000 ml (d) 0.104 ml (e) 0.000107 ml 17&18. Calculate the change in internal energy, E, of a system when it absorbs 40 J of heat from the surroundings, and 30 J of work is done by the system on the surroundings. (a) +70 J (b) 70 J (c) +10 J (d) 10 J (e) 0 J Keeney-Kennicutt, 2009 A2
19&20. How many grams of oxygen are required to react with 4.4 grams of C 3 H 8? C 3 H 8 + 5 O 2 3 CO 2 + 4 H 2 O (a) 12 g (b) 8.0 g (c) 64 g (d) 32 g (e) 16 g 21&22. The oxidizing agent in the following unbalanced reaction is: Ag + H 2 S + O 2 Ag 2 S + H 2 O (unbalanced) (a) Ag (b) H 2 S (c) O 2 (d) Ag 2 S (e) H 2 O 23&24. Suppose you have 10.0 g of each of the reactants, how many grams of Ag 2 S can be produced? Ag + H 2 S + O 2 Ag 2 S + H 2 O (unbalanced) (a) 11.5 g (b) 5.47 g (c) 23.8 g (d) 1.40 g (e) 18.3 g Keeney-Kennicutt, 2009 A3
25&26. Consider the reaction: 2H 2 (g) + O 2 (g) 2H 2 O A scientist actually produced 10.0 g of water in this redox reaction that has an 80.0% yield. How much water should she have produced, if all had gone perfectly? (a) 10.0 g (b) 80.0 g (c) 12.5 g (d) 8.00 g (e) 25.0 g 27&28. Consider this reaction: 2 C + O 2 2 CO. If you had 6 moles of C and 2 moles of O 2 (as shown in the picture below), which picture would represent the final situation? Let = C and = O (a) (b) (c) (d) (e) Keeney-Kennicutt, 2009 A4
29&30. How many moles of HCl were required to make 200.0 ml of an acidic solution with ph = 2.33? (The sucker answers are present.) (a) 0.73 mol (b) 7.3 mol (c) 9.4 x 10 4 mol (d) 0.019 mol (e) 0.023 mol 31&32. How many grams of NaF must be added to 25.0 g of water to prepare a 5.00% solution of NaF? (a) 3.51 g (b) 0.874 g (c) 1.50 g (d) 1.19 g (e) 1.32 g Keeney-Kennicutt, 2009 A5
Keeney-Kennicutt, 2009 A6
CHEMISTRY 101 EXAM 2 Form A SPRING 2009 Section 501 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 acid-base reaction between nitric acid and iron(iii) hydroxide. 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) (b) What is the total ionic equation? Include the charge for every ion. (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. OVER Keeney-Kennicutt, 2009 A7
(5 pts) 34. Consider the titration of 30.0 ml of 0.0500 M HCl with 0.150 M Ba(OH) 2 solution. Calculate the volume (in ml) of Ba(OH) 2 required to reach the equivalence point. (5 pts) 35. Given: water: m.p. 0 o C, b.p. 100 o C heat of fusion = 333 J/g at 0 o C heat of vaporization = 2260 J/g at 100 o C specific heat (g) = 2.03 J/g o C specific heat (l) = 4.18 J/g o C specific heat (s) = 2.09 J/g o C Calculate the amount of heat that must be released to convert 40.0 g of water at 65 o C to solid ice at 20.0 o C (in kj). (1 pt) BONUS: (a) How many times have you looked at one of my homemade videos? ( ) never ( ) once ( ) 2-3 times ( ) 4-6 times ( ) more than 6 times (b) How useful are my homemade videos to your preparation for an exam? ( ) not useful at all ( ) a little useful ( ) moderately useful ( ) very useful ( ) critically useful Keeney-Kennicutt, 2009 A8
SCRAP PAPER OR COMMENTS ON EXAM CHEMISTRY 101 EXAM 2 Form A Spring 2009 Section 501 NAME Keeney-Kennicutt, 2009 A9