Test 2 Name Chemistry 10 Dr. Kline 1 April 2004 Row Seat Lab 8:00 10:30 This test consists of a combination of multiple choice and other questions. There should be a total of 19 questions on five pages; please check to make sure that they are all here. You may use the equation/information sheet and any periodic table provided (page 6). Do not use your own tables, scratch paper or other information. Do not share your calculator. Please turn off all cell phones, pagers and other communication devices; if they make noise, they will be confiscated. Shared calculators will be confiscated. It is OK to tear off the periodic table page; just make sure to do the problems on the other side of the page, reattach it to your test, and write your name on it. Multiple Choice Questions Each of the following 15 questions is worth three points, for a total of 45 points. There is only one correct answer for each question unless it is stated otherwise for a given question. Answer each question by circling the letter(s) corresponding to the correct choice(s); in other words, if there is more than one correct answer, circle all of them. It is not necessary to show work for these questions; however, you may write on the exam. 1. How many atoms of oxygen are in one mole of sucrose, C 12 H 22 O 11? a. 11 b. 22 c. 6.6 x 10 24 d. 1.3 x 10 25 e. 6.0 x 10 23 2. What is the molar mass of Ca 3 (PO 4 ) 2? a. 325.0 g/mole b. 310.2 g/mole c. 175.1 g/mole d. 135.1 g/mole e. 215.2 g/mole 3. Which of the following compounds has the highest percent by mass of hydrogen? a. HCl b. H 2 O c. H 2 S d. HF e. HBr 4. What is the mass of one atom of platinum to three significant figures? a. 3.24 x 10-22 g b. 1.77 x 10-22 g c. 106 g d. 195 g e. 5.66 x 10 21 g f. 3.09 x 10 21 g 5. Which of the following compounds have the same percent composition as glucose, C 6 H 12 O 6? More than one answer may be a. ribose, C 5 H 10 O 5 b. fructose, C 6 H 12 O 6 c. sucrose, C 12 H 22 O 11 Page 1 of 5 Test 1A Chem 10
6. What is the correct volume reading for the buret below, assuming that the 4 and 5 are in units of ml? a. 4.6 ml b. 4.62 ml c. 5.38 ml d. 5.4 ml e. 5.6 ml f. 4.4 ml 7. Which of the following properties of oxygen gas allowed you to store the bottles of oxygen mouth-up on the lab bench during last weeks Properties of Oxygen experiment? a. Oxygen is not soluble in water. b. Oxygen is soluble in water. c. Oxygen is denser than air. d. Oxygen is less dense than air. e. Oxygen is agoraphobic (abnormally afraid of open or public spaces). 8. Which of the following is/are oxidation-reduction reactions? More than one answer may be a. K(s) + H 2 O(l) KOH(aq) + H 2 (g) b. C 4 H 10 (g) + O 2 (g) CO 2 (g) + H 2 O(l) c. FeCl 3 (aq) + NaOH(aq) Fe(OH) 3 (s) + NaCl(aq) 9. What is the coefficient in front of the water when the equation C 5 H 10 (g) + O 2 (g) CO 2 (g) + H 2 O(l) is correctly balanced? a. 4 b. 5 c. 8 d. 10 e. 13 10. A precipitate is formed when aqueous solutions of sodium sulfide and copper(ii) nitrate are combined. What is the formula of this precipitate? a. Na 2 S b. CuS c. Cu(NO 3 ) 2 d. NaNO 3 e. NaCu 11. What is the correctly balanced net ionic equation for the reaction that occurs when aqueous solutions of barium hydroxide and hydrobromic acid are combined? a. Ba(OH) 2 (aq) + 2HBr(aq) BaBr 2 (aq) + 2H 2 O(l) b. Ba 2+ (aq) + 2OH - (aq) + 2H + (aq) + 2Br - (aq) Ba 2+ (aq) + 2Br - (aq) + 2H 2 O(l) c. 2OH - (aq) + 2H + (aq) 2H 2 O(l) d. OH - (aq) + H + (aq) H 2 O(l) 12. Which of the following compounds is/are insoluble in water? More than one answer may be a. PbS b. K 2 S c. Ag 2 CO 3 Page 2 of 5 Test 1A Chem 10
d. None of them. 13. Which of the following would react with HCl(aq) to give a gas? More than one answer may be a. Na 2 S b. Ag 2 SO 3 c. NH 4 Cl 14. Suppose that aqueous solutions of each of the following pairs of reagents are combined. Which will result in a reaction? More than one answer may be a. Aluminum nitrate + potassium hydroxide b. Ammonium chloride + lead(ii) nitrate c. Iron(III) nitrate and sodium sulfate 15. Given that the reaction represented by the net ionic equation Sn(s) + Pb 2+ (aq) Pb(s) + Sn 2+ (aq) occurs as written, which of the following is true? a. Tin is more easily oxidized than lead. b. Lead is more easily oxidized than tin. c. It is impossible to tell. Problems and Questions Each of the following is worth the indicated number of points, for a total of 55 points. Please show work, with units, to receive credit unless instructed otherwise. Also, be sure to provide all of the information requested for each question. 16. 24 points Complete the following table by providing names for formulas and formulas for names. Please use the naming systems discussed in lecture and lab. a. b. c. d. e. f. g. h. i. j. k. l. Formula Ca(ClO) 2 (NH 4 ) 2 S PbCrO 4 IBr 3 KrF 6 HC 2 H 3 O 2 (aq) Na 2 SO 4 10H 2 O Name Manganese(IV) nitride Hydrosulfuric acid Aluminum carbonate Mercury(I) nitrite Lithium permanganate Page 3 of 5 Test 2A Chem 10
17. 12 points Cocaine has a molecular weight of 303.36 g/mole and the following percent composition by mass: 67.31% carbon, 6.98% hydrogen, 4.62% nitrogen, and 21.10% oxygen. Determine the empirical and molecular formulas of cocaine. 18. 9 points The price of zinc on the London Metal Exchange on Friday (4/26) was $1081.00 per metric ton. The rate of exchange on Friday was $1.22753 per Euro ( ). How many atoms of zinc could you purchase for exactly one million Euros at these rates? Please give your final answer in scientific notation and to three significant figures. 1 metric ton = 1000 kg (exactly). 19. 10 points Balance each of the following equations. State labels are deliberately left out. FeCl 3 + NaOH Fe(OH) 3 + NaCl NiS + O 2 NiO + SO 2 Al + O 2 Al 2 O 3 Ba(OH) 2 + H 3 PO 4 Ba 3 (PO 4 ) 2 + H 2 O MnO 2 + HCl MnCl 2 + Cl 2 + H 2 O Page 4 of 5 Test 2A Chem 10
TEST #2 Spring 2004 Equation and Information Sheet Conversions 1 metric ton = 1000 kg. Avagadro s number = 6.022 x 10 23 Name Solubility Rules for Ionic Compounds q Compounds containing Group IA ions, ammonium, acetate and nitrate are always soluble. q Compounds containing chloride, bromide, and iodide are soluble, except when paired with silver, lead(ii), and mercury(i) ions. q Compounds containing sulfate are soluble, except when paired with strontium, barium lead(ii) and calcium ions. q Compounds containing hydroxide are insoluble except when paired with barium and the alwayssoluble cations. q Compounds containing sulfide are insoluble, except when paired with calcium, barium, strontium, and the always-soluble cations. q Compounds containing phosphate and carbonate are insoluble, except when paired with the always-soluble cations. Page 5 of 5 Test 2A Chem 10