Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm Bk Cf Es Fm Md No LrH HeLi Be B C N O F NeNa Mg Al Si P S Cl ArK Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br KrRb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I XeCs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnFr Ra Ac Rf Db Sg Bh Hs Mt1 23 4 5 6 7 8 9 1011 12 13 14 15 16 17 1819 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 3637 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 5455 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 8687 88 89 104 105 106 107 108 10958 59 60 61 62 63 64 65 66 67 68 69 70 7190 91 92 93 94 95 96 97 98 99 100 101 102 1031.0079 4.00266.941 9.0122 10.811 12.011 14.0067 15.9994 18.9984 20.179722.9898 24.3050 26.9815 28.0855 30.9738 32.066 35.4527 39.94839.0983 40.078 44.9559 47.88 50.9415 51.9961 54.9380 55.847 58.9332 58.69 63.546 65.39 69.723 72.61 74.9216 78.96 79.904 83.8085.4678 87.62 88.9059 91.224 92.9064 95.94 (98) 101.07 102.9055 106.42 107.8682 112.411 114.82 118.710 121.75 127.60 126.9045 131.39132.9054 137.327 138.9055 178.49 180.9479 183.85 186.207 190.2 192.22 195.08 196.9665 200.59 204.3833 207.2 208.9804 (209) (210) (222)(223) (226) (227) (261) (262) (263) (262) (265) (266)140.115 140.9076 144.24 (145) 150.36 151.965 157.25 158.9253 162.50 164.9303 167.26 168.9342 173.04 174.967232.0381 231.0359 238.0289 (237) (244) (243) (247) (247) (251) (252) (257) (258) (259) (260)1A 8A2A 3A 4A 5A 6A 7A3B 4B 5B 6B 7B 8B 1B 2B1 182 13 14 15 16 173 4 5 6 7 8 9 10 11 12Periodic Table of the ElementsCreate assignment, 52120, Quiz 3, Feb 27 at 8:30 am 2This print-out should have 8 questions.Multiple-choice questions may continue onthe next column or page – find all choicesbefore answering. The due time is Centraltime.Msci 18 034018:01, general, multiple choice, > 1 min, fixed.001What is [OH−] in a 0.0050 M HCl solution?1. 5.0 × 10−3M2. 1.0 M3. 1.0 × 10−7M4. 6.6 × 10−5M5. 2.0 × 10−12M correctExplanation:[OH−] = 0.0050 MSince HCl is a strong acid, it completelydissociates and H+is 0.0050 M.HCl*)H++ Cl−Kw= [H+][OH−] = 1 × 10−14[OH−] =Kw[H+]=1 × 10−140.0050= 2 × 10−12MMsci 18 040118:01, general, multiple choice, > 1 min, fixed.002Hydroxylamine is a weak molecular base withKb= 6.6 × 10−9.What is the pH of a 0.0500 M solution ofhydroxylamine?1. pH = 3.632. pH = 4.743. pH = 7.124. pH = 9.26 correct5. pH = 10.376. pH = 9.487. pH = 8.93Explanation:Hydroxylamine is a weak base, so use theequation to calculate weak base [OH−] con-centration (note that this is the approximateequation. Why? Because Kbis very smalland the concentration is reasonable) :[OH−] =pKbCb=q(6.6 × 10−9) (0.0500)= 1.82 × 10−5After finding [OH−], you can find pH usingeither method below:A)pOH = − log¡1.82 × 10−5¢= 4.74pH = 14 − 4.74 = 9.26or B)[H+] =Kw[OH−]=1.0 × 10−141.82 × 10−5= 5.52 × 10−10pH = − log¡5.52 × 10−10¢= 9.26Acid Strength 10 36b18:01, basic, multiple choice, > 1 min,wording-variable.003Which acid is weaker?1. HBrO correct2. HBrO33. They have the same strength.Explanation:HBrO3is stronger; there are more O atomsattached to the central atom in HBrO3, mak-ing the HO bond in HBrO3more polar(and thus more easily broken) than in HBrO.Msci 10 031811:04, general, multiple choice, > 1 min, fixed.004Create assignment, 52120, Quiz 3, Feb 27 at 8:30 am 3Which of the following would be expected toact as a Lewis acid?1. OH−2. NH33. H3O+4. NH+45. BF3correctExplanation:A Lewis acid will have an electron poor re-gion and be able to accept an electron pair.In BF3the boron atom is sharing only 6 elec-trons and therefore would be able to acceptan electron pair.ChemPrin3e T10 0518:99, basic, multiple choice, < 1 min, fixed.005What is the conjugate base of ammonia?1. NH2OH2. NH−2correct3. NH+44. NH35. OH−Explanation:Msci 18 071618:08, general, multiple choice, > 1 min, fixed.006All components are present in 0.10 M concen-trations.I) HCN and NaCNII) NH3and NH4ClIII) HNO3and NH4NO3IV) HClO3and NaClO3Which will give buffer solutions?1. I, III and IV only2. I and II only correct3. II, III and IV only4. III and IV only5. I and III onlyExplanation:Buffers are formed in one of two ways, bycombining a weak acid and its conjugate baseor by combining a weak base and its conjugateacid.HNO3and HClO3are both strong acidsand cannot be used to make effective buffersolutions.HCN is a weak acid and NaCN is the salt ofits conjugate base, CN−. NH3is a weak baseand NH4Cl is the salt of its conjugate acid,NH+4. Therefore 1 and 2 can be used to makeeffective buffer solutions.Msci 46 001419:01, general, multiple choice, > 1 min, fixed.007What is the molar solubility of CaF2? (Ksp=3.9 × 10−11.)1. 6.2 × 10−62. 3.4 × 10−43. 2.1 × 10−4correct4. 3.9 × 10−115. 4.4 × 10−6Explanation:CaF2*)Ca2++ 2 F−Ksp= [Ca2+] [F−]23.9 × 10−11= (x) (2x)2= 4 x3x = 2.1 × 10−4ChemPrin3e T11 04Create assignment, 52120, Quiz 3, Feb 27 at 8:30 am 418:08, basic, multiple choice, < 1 min, fixed.008What is the pH of an aqueous solution that is0.10 M HCOOH (Ka= 1.8 × 10−4) and 0.10M NaHCO2?1. 10.262. 3.74 correct3. 5.744. 2.385.
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