CHEM 162: Exam IPage IPage2Page 3Page 4Page 5Exam Percentage(8) 1. Cn/cb.all of the following statements that are true:fl A . At equilibrium the rate for the forward reaction equals the rate for the reverse reaction.il/ The equilibrium constants, Ko and K., are unitless.V I At equilibrium the concentrations of reactants and products do not change.WA Pure liquids and solids are never included in equilibrium expressions. A- " | ,.tn ( fil e. A very large value for K. means the equilibrium favors products. f"fun'W( yt& tlW fi',"#l'l:ililJ:;.:n:;:;l*",?."*Trff#t"oi:,1*" are fruar ^ + h * c + funflil fr. Decreasing temperature will increase the equilibrium constant for an exothermic reaction.(4)2. Considerthefollowingreaction: Cr2O72-(aq) + H2O(t) ,!i..* 2CrOa2-(aq) + 2[*(uq1orange yellowCnfiV.all of the following statements below that are true:d u. A chromate-dichromate equilibrium system becomes lighter when its pH decreases. nlrJrlr, W2f A chromate-dichromate equilibrium system becomes darker when it becomes $s basic. v WOW1t A chromate-dichromate equilibrium system becomes lighter if sodium hydroxide is added to it.EI d. A chromate-dichromate equilibrium system becomes darker if nitric acid is added to it.(4) 3 Write the equilibrium expression for K for the reaction shown in problem #2,then explain whyadding DI water to an orange chromate-dichromate solution at equilibrium will cause the system to0 '.li,u, h "Vbecome lighter in col-or. ^1.Ko= W'l'!-urJ +lcryol1Urvqffiflf =ft;(ilrrqotrInffiffihb\^^^ t'nth,^4#+w 4t1*,twL{^Wwue,19 v{qilwCHEM 162 Exam 1 - Winter4. For each of the following substances, fiIl in the blank (if appropriate) then classi$ each as(7) strongly or weakly acidic, strongly or weakly basic, or neutral:a. urine, pOH:9.25b. blood, [H*]:4.0"10-8Mor: q.1{strongly @*r. neutralstrongty @ u.iai@eutralFor the problems below, SHOW ALL WORK, including why any approximations are valid.Give all final answers with the correct units and the correct number of significant figures to receivefull credit. Circle yourfinal a.nswer.nr6&2{ bvl'-fi6. Consider K. is 8.9x102 at 480'C for the reaction, AHCI(S) + Or(g) W 2 Clr($ + ZHrO(g).\{€(8) a. A closed chamber is evacuated then filled with hydrogen chloride and oxygen gas, which react at480"C. Calculate the reaction quotient for a system if when the total pressure rs 7 .9 atm, and theCHEM L62 Exam 1 - Winter 2014page 2 of 5For the problems below, SHOW ALL WORK, and why approximations are valid. Give allanswers with the correct units and number of significant figure to receive full credit.Circle your final a.nswer.7. Ascorbic acid, HzCoHeOe(aq), is a form of vitamin C that humans must consume to prevent scurvy.a. If K",=/.Jal0-e and Kuz=1.6x10-12 for ascorbic(8) acid, a solution of KHCuHuOu is. (Circle one) acidicneutralExplain your answer by showing the relevant dissociation and/or hydrolysis reactions and thecorresponding acid and/or base dissociation constants.i (,A r fi-''r{6^u lq, {be 44N,^!f|rhH u}f = Hr * C,Hyli+ Crllo1i't4-il1-$i u;p't iii,i+io, ? o+t- 4,' 4# " t 2rw-o'l'(-- Wr,^^*tt ,Jll- \w";M Wl^r/,7-f\t,A. t .I baUC.(9) b. Calculate the pH of a sample of juice with an ascorbic acid concentration of 0.0023M.(Assume ascorbic acid is the only ingredient in the juice influencing its pH.).? ArC,,ftr0n = lr rl{*!r0, ,,{,:= U.wffifr tO-q)To,wl/haaY;(, - tL ty, +{) i p ' J\,17dr [0 -'; 4 f, = Wrr(\-vY -Y, rlv '(- V/" U' 'Y (- ->-C anill-r I" Y, _b{'Kf[= A.lg\ W uilllr. TnoW.. w ,)Gfr{dq =fu:;l{rto-l , ii."-WW1}q')"ffih n'#:^'il'ff*d'rt*"':W(2) c r, ^{r[;Y*corbic *,0,',1],"'K:'.;.'".;"r..toa * l'6'i0-''wl(4) d. Use the common ion effect to explain why the hydronium ions formed frorn the dissociation ofthe second ionizable proton in ascorbic acid are negligible for the solution described inpartbnTt^, b;,rl l,n\-s{d^t* 4w h,rol^tw |1* fon ttp*) ,""8 '^'l;J"n^r il^t.{{i- {+d[lr,^,* ^it+t^^^fi+ t{ crttr0;,r1nt.[M-kH,t- 6*'fu/ 14-' h^^of i,-|*";;l* .W W,Wffi;^W"d!^hhCHEM 162 Exam l- - Winter 2014page3or5 +lN(6) 8. Consider that the equilibrium for each of the following acid-base systems lies to the right at25"C:HCOOH(aq) + CHTNHT(aq) =-'+ CHTNHT*(aq) + HCOO(aq) Wr[11lr>HC0gCHTNHT(aq) + HlOr(aq) :F--$ CHTNHT-(aq) + lOr(aq) (tfr1[lfl, > n;HIo,(aq) + HCoo(aq) * HCooH(aq) + ro,-(aq) V+W- t TgrtTn-Rank the bases in terms of increasing strength: /rl .lt|jr'weakest base. (a?NH,strongest baseFor the problem below, SHOW ALL WORK and give answers with the correct units and thecorrect number of significant figures to receive full credit. Circle your final answer.(8) 9. The formation of ozone in the upper atmosphere is critical for life on Earth since it preventsharmful solar UV light from reaching the Earth's surface.Calculate the equilibrium constant for the formation of ozone, Or(9 + O(S) S Or(g),usins the followine:K= 8.2x10'2sK"= 5.8x10-34IV,,lh.t0rr 0 ?* 0tYo"10. Hydrocyanic acid, HCN(aq), is colorless and extremely poisonous. Calculate the Ku for HCN(aa)V A.19-y, Y- K(('!a{W?rI, iNo,(g) # 1*o,*, + f,orstUtrf o,(s) + No(g) @ No,(s) + o,(s);ff+ 0 ?r===tWWr, + Au "-) 0l +Nffi;rw-q*(I2) if a0.T5MsodiumcyanidesolutionhasapH of lL.54.PrepareanlCEtableandwritetheequilibrium expressionfor the appropriate dissociation or hydrolysis reaction to receivefull*edit' Nn0{ti -? filao r,#; FH,ll fq - p0l+=t4*-tt.${CU;rAoo-+tqJ r4f r' {oll=T$L :i{ v -', r?o f 'l'llll=W1irfi-'rt " {r;-lf qrj - -t- = (A!n'to\'r-0 ffi- a.19-y I1f_EWn./,v JL, -r,J 3 'dt ' -- = 1.t/,lu>r lv ,,t. IW a$-v olf-lqtTlrw' .-' ' -tv Itk,W{6 ,rld.L,brlTt'CHEM 162 Exam 1- Winter 2014Check all of the following statements that are correct:rU p HSeOs-(aq) is an Arrhenius acid and aBronsted-Lo*ty u.iA. lffflgft H2PO3-@q) is a Bronsted-Lowry acid and a Lewis acid.d7" HSeO3-(a4) is a Bronsted-Lowry base and a Lewis base.g/c HSeO3-(a4) is a Bronsted-Lowry base and a Lewis base.M a. H2PO3-(aq) is the conjugate acid of HPO34(aq).;ftt(6) 11. Considerthefollowingreaction: HSeO3 (aq) + Hz\O{(aq) @n1e. HSeO3-@q)is the conjugate base of H2PO3-(aq). tM r. HzPor- is a stronger base than Hzo. fiOPflO,iS O ${ - ,Gdd,h ifi c+*1 beW r(ExrRA .REDIT (6 points): t t W l4,V,* llr0gtult""{For the problems below, SHOW ALL WORK and. giv{answers with the correct units and number ofsignificantfigures to receive full credit. Circle yourfinal dnswer.When using the quadratic equation,show the values for a, b, and c, the value inside the square root, and the two values for x.The first