Exam 1 Fall 2005

Exam 1 Fall 2005 - Chemistry 105a First letter of PLEASE...

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Unformatted text preview: Chemistry 105a First letter of PLEASE PRINT YOUR NAME IN BLOCK LETTERS last name Fall, 2005 Name: Exam #1 Sept 15, 2005 USC I.D.No: Dr. Robert Bau T.A.'s Name: Lab: (M aft. / M eve. / Tu morn. / Tu aft. / W aft. / Th morn. / F aft. / none) (Elease circle lab section above) Question Maximum Score j Grader foints 1 12 _4 T 2 16 + 4 3 L_ 10 a 4', 5 14 k€7 L 6 + 12 I 1 7 12 L 8 12 _i E Total 1— 100 1: J 1' VIII 1 2 H II III IV V VI VII He 1.00797 4.00260 _.3_._._T_.] 5_| 6 7 s 9 1o Li Be B C N O F Ne 6.941 9.01218 10.811 12.0111 14.0067 15.9994 18.9984 20.179 _J 1 1 1 2 1 6 1 7 18 Na M g S Cl Ar 22.98% 24.305 L 32.064 35.453 39.948 19 20 21 24 25 26 27 34 35 36 K Ca Sc Cr Mn Fe Co Se Br Kr 39.0983 40.08 44 9559 51.996 54.9380 55.847 58.9332 78.96 79.904 83.80 42 43 44 45 Mo Tc Ru Rh 95.94 98.9062 101.07 102.905 52 53 54 Te I Xe 127.60 126.904 131.30 55 56 57 74 75 76 77 84 85 86 Cs Ba La W Re 0 5 Ir Po At Rn 132 905 J_137.34 138.905 183.85 186.2 190.2 192.2 (209) (210 (222) 87 88 89 106 107 108 109 Fr Ra Ac (223) 226.025 227.027 58 59 60 61 62 63 65 66 67 Lanthanides Ce Pr Nd P m S m E u G d T b Dy Ho 140.12 140.907 144.24 150.35 151.96 . 158.925 162.50 164.930 90 91 92 93 94 95 97 98 99 Actinides Th Pa U Np P u A m Bk Cf E s L 232.038 231.035 238.029 237.048 (244) (243) (247) (251) (252) I have observed all the rules of academic integrity while taking this exam signature Question #1 (12 pts) (a) (4 pts) Carry out the followin operations and express the answers with the appropriate number 0 significant figures J r. u» o-fi’ 47?.092 r—-——-’ q79-é (i) 0.98 + 3.857 - 51.56 + 1021.9 - 0.5678 =7 30 (ii) (5.48579x1028) x (1.98x10-6) + (9.1178x10-8) : 1mm? x w 7 row“ off 3 Nix '0 " (b) Fill in the blanks: 238U i 3 ts The atom 92 has 7‘2 rotons, 72 electrons and / 1" neutrons. P —— P —— .— 51 2+ ii 3 ts The ion 23V has ‘3 rotons, 2 / electrons and 2’ neutrons. P ———— P —— _ It? — 53 (iii) (2 pts) What has 53 protons, 54 electrons and 75 neutrons ? Answer: Question #2 (16 points) (Circle correct answers) (a) Calcium phosphate is (i) CaP (vi) Ca3(P03)2 (ii) C21ng (Vii) CaPO4 (iii) Ca3P2 (viii Caz P04 3 (iv) CaPO3 W 6’“ (v) Ca2(P03)3 (x) none of the above (b) Aluminum nitride is ——-7 (vi) A1(N02)3 (ii) AlN3 (vii) A1N03 (iii) A13N (viii) A13N03 (iv) AlNOz (ix) A1(N03)3 (V) A13N02 (x) none of the above (C) Lithium sulfide is (i) LiS (Vi) Li(SO3)2 (vii) LiSO4 (iii) LiSz (viii) Li2504 (iv) LiSO3 (ix) Li(SO4)2 (v) Li2803 (x) none of the above (d) Magnesium perchlorate is (i) MgCl (vi) Mg(CIO3)2 (ii) MgClg (vii) MgClO4 (iii) Mngl (viii) M2CIO4 (iv) MgClOg, ix) Mg(ClO4 ‘—- (v) Mg2C103 (x) none of the above (e) Coba1t(III) carbonate is (i) CoC (vi) Co(C03)3 (ii) C03C (vii) CoCO4 (iii) CoC3 (viii) C03CO4 (iv) C0C03 (ix) C0 C04 1/ (v) CosCOs 44°“)? (f) Ammonium peroxide is (i) NH3O (vi) NH402 (ii) NH40 (vii) (NH3>202 (iii) (NH3)2O (W "“’ (iV) (NH4)2O (ix) (NH4)2(02)2 (v) NH302 (x) none of the above Write the names of the following compounds: (g) AgCN (*0 P453 Question #3 (10 points) Balance the following equations. (a) NH3 + 02 —) N02 + H20 (3 pts) y 1,4: law; + 02 -—+ N0; +139” N l7“: 2N113 ,1. 0; “END; {Zilla 05“: ZNHJJ‘EOzfl'zA’O; *2/110 , 4471‘.” m «4 0R 4””: 4‘ 70; '9 4U°z f (HZ—O gt,ng 44' fit Cay/49ffiao4' WW (b) A14C3 + H20 '—> A1(OH)3 + CH4 (3pts) [‘4 bat: 4‘96? f £11.: -—9 {344(011); rel/v 4 6‘1..- “ycg 4. #LO ._.., 4341(01123 11:??qu /4 54: 4‘46: (—l‘ljllkb—a 4M(0H)}+.7CH9 & 6u. felt") ItA—nfwcr (C) C5H7N30 + 02 —> C02 + H20 + NO (4pts) 4 ’9“: €{H7N30 + 0; —-—>/fi‘ ¢OL+Hto+—,vo N b“: Cy/‘(7U30 4- 0L —-' 5""; 1" HL°+/EU° f, b“, CXH7A/30 4. a; .._, 5’CD;+I:‘E3IJLO 1' Eye 0 541: CIA/7M“) f rig—0L --3 5'50; f' flab 1- ?m:> 0‘ Z£5h7yso 4‘ .éf-GL -—’ {a CGL—f 79L: 4- (MO M 9“!”7’9" * 37/ O; A 2005' + My); +le/o 4A7 of flu“ 44m“ ecu/boa a; 451:1.)ch‘”- Question #4 (12 pts) (Please Show Work!) (a) (6 pts) A softball pitcher throws a ball at a speed of 56 miles per hour. At that velocity, how many seconds does it take for the ball to travel from the pitcher's mound to home plate, a distance of 38 feet? (Given: one mile = 5280 feet). / “174 //Hnsr 3{ c I“ (3‘7 té>( " > 44) -'-' 0-44 AL“: 5’2’0 ft 5" M714! 1 htuv ~—————-———————. (b) (6 pts) How many molecules of P4 are there in eleven nanograms of P4? (Given: Avogadro's number = 6.022 x 1023) Wfil‘wlto/ wa'fbr (lino/64’ mall) 97 ’49 : 4—1 ?I 1' IZS‘J/mo/é 13 (n x I5} 4% ’ MM?) [2+2 ’9 / rho/4. lag l .7 512x IO 3 menu/d 07 ,0“ __________________________—__————-«““—""“ Question #5 (14 points): (please show work) An unknown compound Q contains only carbon and hydrogen. 1.000 g of Q is totally burned in an excess of oxygen (02) to form carbon dioxide and water. The amount of water obtained in this manner weighs 1.422 g. (a) How many grams of C02 were obtained in this experiment? (7 pts) (Hint: first figure out how much hydrogen was in the original one-gram sample of Q). flao/u Maw“: #20 .' /+/+Ié: IFJ/mah 40;: “if/(#16: (puff/nah. 2 H quy : (/qu. fi,o)(——Z—-—~): O-ll‘fjh Wm 0 C foc'uad unfatowu -"—‘ /~0"‘"0"’I: O’P4l ¢ ( _ 3 0,, MM! '7 C02. : 0.??Zj c) (L; a "' ‘ 2 COL/Ian-ud _____________________.._.——- (b) What is the empirical formula of unknown compound Q? (7 pts) £:H : 0-f‘rlJ6 .' O‘U'Pffl [2.0/7/mo/4 loooi‘i/n-u4Jr = 4070: web < .' 0~/$‘(7 rum/I 0,070] ‘ f ' 0-1517 b'“"“' ‘7 Im‘l’wmhwé": 6" a ’ (c.0701) 1‘ /.00: 29‘ “Au. 2a or.“ h 6:}! = {.00 13.25" = “27* Question #6 (12 pts) (please show work) A 15.0 g sample of lithium is reacted with 15.0 g of fluorine to form lithium fluoride: ( 2 Li + F2 -—) 2 LiF After the reaction is complete, calculate the amount of each component left at the end of the experiment: (a) grams of LiF; (b) grams of Li; (c) grams of F2. / 4L: ma,“ d7 Li: (Alto; Ll.)(‘n:-0/———) 7 2:17 l’hb/l’.’ Ll. 47/ L; OwF W‘ltf 67 1‘; I {/5102 .: 0-?5‘? rho/4v QFL (I7flf); Fp gn- ‘kud 4 2H VGA'O- (7 LI v‘v FL ‘49 car, MA “flak/:44”, fly Ari/o4cfi‘m/ if‘ if alvioar no? 7(1- qu, Ac.“ LawleL It £4 {1‘ Aha-36‘“, tuna/44¢" (4) 45/414410 Lil: flodtvuvd. u?” A". (“7‘ WM 7 r (“7*”); “F g / ““I‘ F; / mole L,‘F €V‘W’ 0 LI! f44d4d: (0-3”va o7 FL)(.Z_’“.”.*’_L”_L)<_€1L‘7_‘L : (Mo/4‘. 5f Fl 19710014“ 6) L: /‘fr 4 46' “a ‘7 I’¢a¢./.'¢n. 5‘ /5'.0 ~53! = 7-5é Z amrzaut4oL L; {(7, a", (C) grew; 47 FL /¢.ff of (not to r‘t : 0.0 rdluf (FL 4:4 KL £4.““>6.“7 V44f4wf—) Question #7 (12 pts) (please show work) anJo/w'uj A solution is prepared by 10.8 grams of ammonium phosphate in enough water to make 100.0 mL of stock solution. A 10.0 mL sample of this stock solution is added to 50.0 mL of water. Calculate the concentrations (molarities) of ammonium ions and phosphate ions in the final solution. #25. (l\_lgtez this problem is almost identical to one of the Homework Questions: Ch. 4, W) flaw/w man (mo/cu!“ «44741) 5] (Ana); pa, ,‘J; 3(u)+ (1(H)+/°r¥(0) 2‘ 3(Iv)+ I20) *3/4' 40‘) = /+7i/mol(, : a .0725’ 14.01- g (wrQJ/vo [Wui‘ (wry),va ) 9v (Inf; 0 {rt/H“); pc¢)( "r‘i; (Vim/lyre“ _ . 3- 14}; Lot/I larval-ch 9-073J' 1444/41 #7 [/06] aux 3(0472r): 0-2/75- mom 0? [Mran 0- 0 7ZJ’ mole: an :5“ é’onunA/‘A‘nr- 3‘ _._7_.__....___._______' [flea] : = 07er o./ L, 0'2/7J‘ mol¢ f. I [4”qu :' : 2.’7.S'M 0-! L Aff... DIM/yr» I fa,“ you...“ .—. lamg+ro ml. a game (a.f¢_/) My, (mm-u) : Mil/L (final) .7- , - FN [was] (0.725M)(/0~L)— (Ml) ((onL) Ml: o-Iz/ M [your F» [IV/wjr (2,/75‘M)(/°”'L)= (~z)(é°‘“") MZ = 0‘353/‘4 [NH.,]* Question #8 (12 pts) (please show work) A mixture of RbBr and RbNO3 is 55.5% rubidium (Rb) by mass. Calculate the mass percent of RbBr in the original mixture. Rb / // R5 '24 To,“ 7W4 /00/ Ly ANI‘§;«~< / N A6: mix/Ian. . 14f flxuu 44. X Z e" r 0 55337. 07 Away 4444 Uw’djww X; (IN-X); fl fléluoj £6 7344:ng R6 Lu/jqfléér Z {Vj)</?6r/3r) o°J‘-J’ :- —-—— 3 '5 (¥)(’flhr+7fi) {a I7)(Y) R6 Wm «7 AM «2. (“a”); ’7 "35”! " (’“o’x)(,euwz(°)) In; - (loo—x)<8r A—ffifi’ #8) : (loo’x>(o.ro°a) 77154 (Anal; 47fl6 in. /"°J ‘9 W7""”’* “'4 “Hr/7} 40: (0.4"?)(1) + (/00'{)(0.J’fo) = 4-5,,“ (0«r17_ o..\'fo)(x) 4— $00.0 = {J'J' 5”.0-—-J’:-" 2'5' x: ———————-—- : __.,Z_= o-J'io’a4-I7 0-013 39’7/ RbBr 5", [1441! 90 fl Ifit’rlu wry-3n“ “719‘ch 67 {W} (-4 70 ...
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Exam 1 Fall 2005 - Chemistry 105a First letter of PLEASE...

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