Exam TwoCHM 203 (Dr. Mattson)24 September 2004Academic Integrity Pledge:In keeping with Creighton University’s ideals and with the Academic Integrity Codeadopted by the College of Arts and Sciences, I pledge that this work is my own and thatI have neither given nor received inappropriate assistance in preparing it.Signature:Instructions: Show all work whenever a calculation is required! You will receive credit for how you worked each problem aswell as for the correct answer. This exam is worth 50 points. BOX YOUR ANSWERS!1. (3 pts) Determine the number of moles ofammonium carbonate present in a 82.55 gsample.2. (3 pts) How many moles of fluorine atoms arepresent in a 107 g sample of phosphorustrifluoride?3. (3 pts) Use Avogadro’s number to determinethe actual number of carbon atoms present in aspeck of carbon with a mass of 1.3 µg.4. (3 points) Balance the following equation withthe smallest whole number coefficients.C2H6S + O2 €  →  CO2 + H2O + SO25. (3 pts) Iron(III) nitrate reacts with sodiumsulfide to produce iron(III) sulfide and sodiumnitrate. Balance the equation for this reaction.6. (3 pts) What mass of H2O is needed to reactcompletely with 14.3 g Ca3N2? [MM (g/mol):Ca3N2 = 148.3; H2O = 18.0]Ca3N2 + 6 H2O €  →  3 Ca(OH)2 + 2 NH37. (3 pts) Consider the following balancedequation:4 CuSCN + 7 KIO3 + 14 HCl €  →  4 CuSO4 + 7 ICl + 4 HCN + 7 KCl + 5 H2OSuppose 50.0 g CuSCN, 130 g KIO3, and 25 gHCl were allowed to react according to theequation. Determine the limiting reagent.[MM(g/mol): CuSCN = 121.6; KIO3 = 214.0; HCl= 36.5]4 CuSCN + 7 KIO3 + 14 HCl €  →  products8. Again refer to the chemical equation in theprevious problem. If 480 g CuSCN wereallowed to react with excess potassium iodateand hydrochloric acid according to the equation,(a) (3 pts) determine the theoretical yield of iodinemonochloride. [MM: ICl = 162.4 g/mol](b) (3 pts) determine the actual yield (in grams) ofICl if the reaction occurred with a 78% yield.9. (3 pts) In thereaction shown, is A and is B.Which is thelimiting reagentand what is thebalancedequation? Think!L. R.Balanced equationA.A25 A2 + 4 B2€  →  4 AB2 + 3 A2B.A2A2 + 2 B2€  →  2 AB2C.B25 A2 + 4 B2€  →  4 AB2 + 3 A2D.B2A2 + 2 B2€  →  2 AB2E.noneA2 + 2 B2€  →  2 AB2 + 3 A210. (3 pts) What is the molarity of a solutionprepared by dissolving 24.0 g potassium iodidein water to make 500.0 mL solution?11. (3 pts) A compound of sodium, sulfur, andoxygen contains 29.08% Na, 40.56% S, and30.36% 0. Which formula is correct?A. Na2SO3B. Na2S2O8C. Na2SO4D. Na2S4O6E. Na2S2O3Show work here12. (3 pts) The simplest formula of a substance isfound to be CH2O, and its approximate molarmass is found by experiment to be 93 g·mol–1.What is its exact molar mass?A. 30.0 g·mol–1B. 87.0 g·mol–1C. 90.0 g·mol–1D. 92.0 g·mol–1E. 93.0 g·mol–1Show work here13. (3 pts) How many moles of Na2S are requiredto react completely with 65.00 mL of a 0.25 Maqueous Al(NO3)3?2 Al(NO3)3 + 3 Na2S €  →  Al2S3 + 6 Na2NO314. (7 pts) Circle each of the following as either “I”for ionic, “CM” for covalent molecular or “A” foracidic or “E” for element. Then name each.Circle:Printed Name:BrF5I CM A ECuSO4.5H2OI CM A EMg3(PO4)2I CM A EHClO2I CM A EKClO2I CM A EHNO3I CM A ES8I CM A EHIO3I CM A EN2O3I CM A ENaC2H3O2I CM A EO2I CM A E(NH4)2Cr2O7I CM A E15. (1 point) Print your name here:Your exam score (50 possible): Determine your grade:A > 46.5; B+ > 43.5; B > 41.0;C+ > 37.5; C > 34.00; D > 30.00Answers:1. 0.86 mol ammonium carbonate2. 3.65 mol F atoms3. 6.5 x 1016 carbon atoms4. 2 C2H6S + 9 O2 €  →  4 CO2 + 6 H2O + 2 SO25. 2 Fe(NO3)3 + 3 Na2S €  →  Fe2S3 + 6 NaNO36. 10.4 g H2O7. HCl is the limiting reagent.8. (a) theoretical yield of iodine monochloride =6.91 mol ICl = 1122 g ICl; (b) 875 g ICl9. D]10. 0.289 mol KI/L11. E12. C13. 0.0244 mol Na2S14.Printed Name:BrF5CMbromine pentafluorideCuSO4.5H2OIcopper(II) sulfatepentahydrateMg3(PO4)2Imagnesium phosphateHClO2Achlorous acidKClO2Ipotassium chloriteHNO3Anitric acidS8EsulfurHIO3Aiodic acidN2O3CMdinitrogen trioxideNaC2H3O2Isodium acetateO2Eoxygen(NH4)2Cr2O7Iammonium