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2 PART A. (4 Pints each) Chem. 15 Exam # 01 Fall Day Test 1. What element(s) is/are underging xidatin in the fllwing reactin? a. Only C in methane b. Only C in carbn dixide CH4 g O( g) CO g HO g c. C in bth methane and carbn dixide 4 t 4 d. Bth C and H in methane e. Only O in xygen. 75 ml f 1.0 M KOH is diluted t 00. ml by adding abut 15 ml f water. What is the apprximate new cncentratin f KOH? a. 0.8 M c. 0. M e. 0. M 75mL 1.MKOHx 0.49MHCl b. 0.4 M d. 0.5 M 00mL. g aluminum brmide is disslved in enugh water t make 15 ml f slutin. What is the apprximate cncentratin f the brmide ins? a. 0.5 M b. 0.1 M c. 0. M d. 0. M e. 0.4 M MM AlBr 7.0 x g/ ml galbr 1mlAlBr x /0.15L0.090 ml/ L0.090M AlBr 1 67 g Cl 0.09 x 0.7M 0.M 1 sig. fig. 4. Excess zinc is added t 150 ml f 0.90 M HCl. The reactin is: Zn s HCl aq ZnCl aq H g. Apprximately what vlume f hydrgen gas is prduced at STP (0 ᵒC and 1 atm). a..0 L Zn s HCl aq ZnClaq Hg b..0 L Excess 150 ml?ml c. 0.5 L d. 0.8 L 0.90M e. 1.5 L 0.9 ml HCl 0.15L 1ml H x x ml H L 1 ml HCl ml f hydrchlric acid is in a beaker. What is its apprximate cncentratin if 60.0 ml f it is HCl aq KOH aq H O l KCl aq neutralized by 5 ml f 0.80 M KOH? The reactin is: a. 0.4 M b. 0. M c. 0.7 M d. 0. M e. 0.5 M q HCl aq KOH aq H O l KCl a 60.0 ml 5 ml?m 0.80M 0.8 ml KOH 0.05L 1ml HCl x x L 1 1ml KOH Cnentratin HCl. 6. The density f an unknwn gas is 1.g/L at STP. What is the mlar mass f the gas? a. 54 g/ml L atm b. 18 g/ml K V RT K ml.4l c. 8 g/ml PV nrt; n P 1atm ml d g/ml 1.g.4L e g/ml MM x 7.6 g/ ml L ml 0.08 ml HNO 0.060L 0.08 ml HCl At STP, 1 ml =.4 L ml H.4L 1 1ml nrt r use V P V x 1.5 ml M HCl L L

3 Chem. 15 Exam # 01 Fall Day Test 7. Which f the fllwing gases has the secnd highest average velcity at 00 K? a. Cl O RT vrms. S the smaller the mlar mass, the higher the average velcity b. SO M c. SOCl r they all have the same kinetic energy which equals 0. 5m v. d. Cl This gives the same cnclusin. e. All average velcities are the same. MM SOCl , ClO 87, SO 80, Cl Helium at atm is in a 50 L cntainer. N at at atm is in a 0 L cntainer. Bth cntainers are cnnected t a balln whse riginally vlume is zer. The cnnecting valves are pened and the balln is filled. At equilibrium, the pressures in the cntainers and balln are abut 1 atm. What is the apprximate vlume f the balln? a. 110 L b. 10 L c. 150 L d. 170 L e. 190 L PV nrt cnstant; PV P V ; Initially ignre N and calculate fr He alne. He He P atm Vf V1 50L x 100L P 1atm He 1 He f N N N 1 f 1 N Pf 1 1 f f P atm Similarly, V V 0L x 90L 1atm V f V V 190 L; V V V V L He N balln He N f f f As a gas expands against an external pressure f 1.70 atm frm 1.0 L t 18.0 L, it lses 800 J f heat t the envirnment. what is its change in internal energy, ΔE? (Recall, 101. J = 1 L atm.) a. 1,800 J 101.J b. -00 J q800 J; wpextv 1.70atm6.0L x 100 c. 00 J L atm d. -1,800 J E qw1,80j 1,800J e J 10. An dd way t measure mass. An unknwn mass f water is in a Styrfam calrimeter f negligible heat capacity. The initial T f the water is 5.0 ᴼC. After 100. g f irn at 65.0 ᵒC is added, the equilibrium T is 15.0ᴼC. What is the apprximate mass f the water? The specific heat f irn and water are 0.45 J/( g ᵒC) and J/( g ᵒC), respectively. a. 50 g b. 70 g c. 90 g d. 10 g e. 140 g q Fe q HO 0 m C T m C T 0 Fe HO Fe s Fe HO s HO 0.45J 4.184J g C g C, J/ g z 0 g C z C J z 54g

4 Chem. 15 Exam # 01 Fall Day Test 11. Using Hess s Law, calculate ΔH fr the fllwing reactin: CCl g 4HCl g CH g 4Cl g Use the fllwing reactins and ΔH : a kj b kj c kj d. 14. kj e. -16,5 kj C s H g CH g H 74.6kJ C s Cl g CCl g H 95.7kJ H g Cl g HCl g H 9.kJ C s H g CH g H kj CCl g C s Cl g H kj 4HCl g H g Cl g H 9.kJ 184.6kJ CCl g 4HCl g CH g 4Cl g H 05.7kJ Hw many mles f phtns are cntained in a burst f yellw light (589 nm) frm a sdium lamp that cntains 609 kj f energy? a. 1 ml b. ml hc 6.6x10 4 J sx10 8 m/ s x10 J Eph 1phtn hf.8x10 J r E 9 ph c. ml 589x10 m 1phtn d. 4 ml 609, 000J 1phtn 1ml phtn e. 5 ml x x.00ml phtns x10 J 6.0x10 phtn 1. Which electrn rbital resembles a dumbbell r peanut? a. s c. f b. p d. d 14. Hw many unpaired electrns des a sulfur atm have and is it diamagnetic r paramagnetic? a. 4 and paramagnetic b. 4 and diamagnetic c. and paramagnetic d. and diamagnetic e. Nne f the abve 15. An electrn in which electrn rbital requires the greatest phtn energy fr it t be inized? a. 1s b. p c. p d. d e. 4s It is analgus t being in a well--the deeper the well, the greater the K.E. needed t 16. Which set f quantum mechanical numbers fr an electrn in an s, p, d, r f rbital is nt pssible? a. d rbital: n=4, l=, ml =, and ms = +1/ b. p rbital: n=, l=1, ml = 0, and ms = +1/ c. 5p rbital: n=5, l=1, ml = -1, and ms = +1/ d. s rbital: n=, l=0, ml = 0, and ms = -1/ e. 5f: n=5, l=, ml =-, and ms = +1/ e. g Full rbitals have n unpaired electrns. S Ne s p p p p p thrugh the baseball ut. 1 s electrns are the deepest in the well. x y z

5 Chem. 15 Exam # 01 Fall Day Test 17. Arrange the fllwing atms and in frm smallest t largest in size--n, N -, O, Ne. a. Ne, O, N, N b. Ne, O, N, N c. ONeN,,, N d. ONeNN,,, e. N, Ne, O, N The fllwing reactin shws the reductin f irn (III) xide t irn by carbn: Fe O s C s 4 Fe s CO g H kj Initial cnditins 50.0 g 7.0 g T save time the mlar mass f irn III xide is x55.8+x16 = 160. g/ml 18. What is the apprximate standard enthalpy f reactin fr 4 g f carbn, that is, 4g C are used up? a. 10 kj b. 0 kj c. 50 kj d. 100 kj e. 150 kj kj 4 1 ml C 4 gc H gc x x kJ ml C 1g Apprximately hw many grams f irn (III) xide remain after 4 g f carbn have reacted? a. 5 g b. 5 g c. 0 g d. 10 g e. 15 g 4gC 1ml C ml Fe O 160g Fe O 1 1g mlc 1ml x x x gfeo remaining xide gFeO 5.6 used up

6 Chem. 15 Exam # 01 Fall PART B (Each prblem is 1 pts) Day Test I L f ammnia gas at rm temperature ( ᵒC) and 70. trr are bubbled thrugh 150. ml f 0.75 M sulfuric acid in a 500 ml glass beaker. The acid-base neutralizatin reactins is: (a 1 ) (5 pts) What is the maximum yield in mles fr the ammnium sulfate? JUSTIFY. 70trr 1atm P x 0.961atm 1 760trr 0.961atm4L PV PV nrt; n 0.159ml NH RT L atm K ml K ml NH NH g H SO ( aq) NH SO aq SO ml NH x 4 4 ml NH 4 SO 4 1 ml NH Smaller is crrect answer 0.75ml H SO 0.15L L 1ml NH SO x x 0.11ml NH4 SO4 1 1mlHSO4 (a ) ( pts) Suppse the actual cncentratin f ammnium sulfate is 0. M. What is the percent yield f ammnium sulfate? 0.ml 0.15L x ml ammnium sulfate L 1 actual yield trr % yield x100% 6% theretical yield trr (b 1 ) (4 pts) Cmplete and balance the fllwing precipitatin reactin. Yu must include (s) and (aq) fr credit. Al CH COO aq NH S aq 4 Al CH COO aq NH S aq Al S s 6NH CH COO aq 4 4 (b ) (1 pt) What is (are) the spectatr in(s)? NH4, CHCOO

7 Chem. 15 Exam # 01 Fall Day Test II. In parts (a) and (b) yu will calculate hw much ethanl is needed t bring a cup f water t the biling pint at ne atmsphere. The specific heat f water is J/g /C. The fllwing reactin will be useful fr sme f parts (a)-(c). CHOHl Og CO g HOg H 1,5 kj 5 (a) (4pts) Hw much heat in kj will be required t raise the temperature f 50 g f water frm 5 C t 100 C? 50g 4.184J 75 C 1kJ qmcst x x x 78.5kJ 1 g C 1 10 J (b) (4pts) Suppse an alchl lamp is used t heat the water. Suppse further that all the energy released by the burning ethanl flame is transferred t the water. Hw many grams f ethanl are required t heat the water? USE 100 kj AS THE ANSWER FOR PART (a). THIS WAY PART (a) CAN BE MISSED WITH NO LOSE IN CREDIT. q H 1, 5 kj / ml C H OH surr 5 100kJ 1ml CH5OH 46.0g x x 1 1, 5kJ 1ml C H OH 5.7g Aside, the actual amunt needed t heat the water is.9 g. 78.5kJ 1ml C H OH 46.0g 1 1,5kJ 1ml C H OH 5 x x.9g 5 (c) (4pts) What is the the right may be useful. H f f C H 5 OH? Sme f the infrmatin in the table t H H CO H H Og H C H OH H O f f f 7 f x 1, x 1, 5 1, kj / ml ΔH f Mlecule (kj/ml) CO (g) -111 CO (g) -94 H O (g) -4 H O (l) -86 Nte, t grader. If answer is kj/ml, mark it wrng and bring t my attentin.