Solved MCQs - Preparatory Chemistry | CHEM 1301, Assignments of Chemistry

Download Solved MCQs - Preparatory Chemistry | CHEM 1301 and more Assignments Chemistry in PDF only on Docsity! Homework 12 (Chapters 8 & 12) Name _Ke Section: CHEM 1301 - 003 (print your name) Due: Tuesday, December 4", 2007 1. A compound that contains carbon, hydrogen and oxygen is found to have an empirical formula of C3H,O. If the molar mass of this compound is 224 g/mol, what is its molecular formula? (a) C3H,O Malar moss of Calg: axtataxr +16 = 56 8huo! c (b) CisHa00s |, __Mnolas mans of compound = 224 Yd oS Ses ©) Ci2Hi6O« Woolas mass o& empirical formula 56 dAucl : (d) CeHsO2 (ec) CoHi20; Meleculor formala 4 (Cag) = Ca ted, 2. Determine the simplest formula of the compound with the following mass percents of the elements present: 17.9% Fe, 51.3% bromine and 30.8% oxygen. @ Fe(BrOs) Assume (vg Sample (b) Fe(BrO), 1%44 a ae 0,321 wol Fe are eas (c) Fe(BrO2)3 a Fe Br 0, (d) Fe(Br03)3 S.agGef lS ao, anetbe (ec) Fe(BrO2)2 : “= =143 wot O 3. Strontium periodate has the formula Sr(IO4)2. Calculate the mass percent of oxygen in = A Melos wass SttID4)a , 87-62 42 Ct2b.44+4x16.00)= 464.428/wl (b) 3.67% oxygen | welSr(T04)2] Bwel O \b,0090 \23 b (c) 23.0% oxygen (Mel Sr 10,)2| (mol O een E (d) 3.40% oxygen - ©) 27.2% oxygen Ywass = hs 2.272% 4. Which of the following compounds has the most mass percent of oxygen? GB 0 mH RNS REE tes ESE rena B © Lio —™ Asse eee 23209 $e- 32:03, 90% = 74.1% (si i. irerark 16.6 - . am se neat eal eOt tat = es a8 —s a 16.04 ul xloo% = 6% 1% XL \ 6.00 12.04, t ame Twaeto 32°94 Seog OOM = 5B.2K aol Na Swrold | (6.20 5. Choose the pair of compounds with the same empirical formula. Tenniclvesie = Bo040 @ CoH: and CoH CH — empirtal formula - 4 (b) H:0 and H,02 Bg84 >» 100% = 74.1%, A (c) K2CrO4 and K7Cr,07 (d) K2SO4 and K4S207 (e) N2O3 and N04 D e B fa, D 6. A 4.00 g of sample that might contain oxygen is analyzed and produces 7.64 g CO2 and 4.69 g HO. What is the empirical formula of such sample? 64.400 NCOn Lmrole c © Gad Es diergcatimntes naman See — 20teac 4.6944 H20| 1 mol Ha? | 2m (ce) CH3O2 ee ee sadam ea = 0.53hqH ) Ae 30 = 4,009 ~2.0855c~ 0, Sabgt= 1.3990 ade = 0,08¢8 mel O CorrgHos21Oooesa => CrcotleeO, 7, 0.500 g of a compound with molar mass of 180.15 g/mol is used for combustions analysis, and produces 0.733 g CO and 0.300 g H20, calculate the molecular formula. a) CsHsO- 2. T55GEPa| yal Coa tel mot) 12.013C 9.5004 - 0.20096 & CaHli20s Oo ieee Lwnol Os ee = a ze0g¢ A Sentkse © 0,300! was we! so Qh ©, 26624° (c) C7Hi6Os Pe 18,0030! twol tho aS = 0.03889H = °. 5 (d) CoH30, Ot ImslO — eoieemelO CoorbrHoosasOvesb CHO MM.ER =30.03¢/me| a Leb 16.904 , Seema = G00. (Clad) = Cath, 8. What is the mass percent of hydrogen in water? (a) 5.60 \wollhO] Dmolh | holgh (b) 333 Gndatinah ooo © 112 202 = 59 Se Z=\ (d) 88.8 18.023 bao * 70% ar 9. What would the empirical formula be for the molecular compound C6H904? C3H904 (b) C2H302 (c) C3H602 © C6H904 10. What is the molecular formula of a compound given the molar mass of the compound as 186.5 g/mol and empirical formula as C2H7? (a) CaHig Melor mast Coy 2XtR0l +TxI.0] = 3104 afuel (b) CgHog Cink \86,59Anol_ _ - Cilla ve SEs = 6.00 (Coty) = Cuter 11. The compound cupferron is used to separate copper and iron from other metals in solution. An analysis of cupferron shows that it is made up of carbon, hydrogen, nitrogen, and oxygen in the following percents by weight: % C= 46.44; % H=5.85; % N = 27.08; % O = 20.62 What is the empirical formula of the compound? Assume 1°24 sample. (a) C1,5HN304,5 _44.449C | \molC = BAT & ey al —= 2 - * L43mol N (b) C3H4.5N1,50 a 20,6240 ae , © Coltgn302 BSH Se sta wel 16.2050 Ait saes (d) C12H9N604 Caa7Heaqhi.9301.24 3 Cyootla.raNiso O,oo CeHgfls D2