CHEM 10113, Quiz 3 September 28, 2011 Name (please print) All equations must be balanced and show phases for full credit. Significant figures count, show charges as appropriate, and please box your answers! IA Periodic Table of the Elements VIIIA (1) (18) 1 2 1 H IIA IIIA IVA VA VIA VIIA He 1.0080 (2) (13) (14) (15) (16) (17) 4.0026 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.9410 9.0122 10.811 12.011 14.007 15.999 18.998 20.179 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB........ VIIIB........ IB IIB Al Si P S Cl Ar 22.990 24.305 (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) 26.982 28.086 30.974 32.066 35.453 39.948 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.098 40.078 44.956 47.880 50.942 51.996 54.938 55.847 58.933 58.690 63.546 65.380 69.723 72.610 74.922 78.960 79.904 83.800 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.468 87.620 88.906 91.224 92.906 95.940 98.907 101.07 102.91 106.42 107.87 112.41 114.82 118.71 121.75 127.60 126.90 131.29 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.91 137.33 138.91 178.49 180.95 183.85 186.21 190.20 192.22 195.09 196.97 200.59 204.38 207.20 208.98 208.98 209.99 222.02 87 88 89 104 105 106 107 108 109 110 111 112 114 7 Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uug 223.02 226.03 227.03 (261) (262) (266) (264) (270) (268) (281) 1. (6 points) For the reaction between lead(ii) nitrate and potassium phosphate, write the balanced molecular equation, ionic equation, and net ionic equation. Identify the precipitate and the spectator ions. a) molecular equation 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140.12 140.91 144.24 145.91 150.36 151.97 157.25 158.93 162.50 164.93 167.26 168.93 173.04 174.97 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232.04 231.04 238.03 237.05 244.06 243.06 247.07 247.07 242.06 252.08 257.10 258.10 259.10 260.11 3 Pb(NO 3 ) 2(aq) + 2 K 3 PO 4(aq) Pb 3 (PO 4 ) 2(s) + 6 KNO 3(aq) b) ionic equation 3 Pb 2+ (aq) + 6 NO 3 (aq) + 6 K + (aq) + 2 PO 4 3 (aq) Pb 3 (PO 4 ) 2(s) + 6 K + (aq) + 6 NO 3 (aq) Spectator ions are the potassium and nitrate, and precipitate is the lead(ii) phosphate. c) net ionic equation 3 Pb 2+ (aq) + 2 PO 4 3 (aq) Pb 3 (PO 4 ) 2(s) 2. (2 points) You are given a solution that is 0.150 M in CuSO 4. If you dilute 6.00 ml of this solution to 10.0 ml, what is the concentration of the new solution? (0.150 M)(6.00 ml) = (10.0 ml)x x = 0.0900 M 1
3. (4 points) SHOW ALL WORK. You have 0.954 g of an unknown diprotic acid. If 36.04 ml of 0.509 M NaOH is required to titrate the acid to the equivalence point, what is the formula mass of the acid? H 2 A (aq) + 2 NaOH (aq) 2 H 2 O (l) + Na 2 A (aq) 36.04 ml NaOH soln x (0.509 mol NaOH/1000 ml NaOH soln) x (1 mol H 2 A/2 mol NaOH) = 9.17218 x 10 3 mol H 2 A 0.954 g H 2 A/9.17218 x 10 3 mol H 2 A = 104 g/mol H 2 A 4. (6 points) For each of the following reactions, write the balanced molecular equation, or NR if there is no reaction. a) Ba(OH) 2(aq) + 2 HCl (aq) 2 H 2 O (l) + BaCl 2(aq) b) MgCO 3(aq) + 2 HCl (aq) H 2 O (l) + CO 2(g) + MgCl 2(aq) c) MnCl 2(aq) + Na 2 S (aq) 2 NaCl (aq) + MnS (s) 5. (4 points) SHOW ALL WORK. For the following balanced reaction, Mg(C 2 H 3 O 2 ) 2(aq) + 2 KOH (aq) Mg(OH) 2(s) + KC 2 H 3 O 2(aq) if 34.6 ml of 1.80 M KOH is fully consumed, and the final volume is 45.0 ml, what is the expected concentration of KC 2 H 3 O 2? 34.6 ml KOH soln x (1.80 mol KOH/1000 ml KOH soln) x (1 mol KC 2 H 3 O 2 /2 mol KOH) = 0.03114 mol KC 2 H 3 O 2 0.03114 mol KC 2 H 3 O 2 /0.0450 L soln = 0.692 M KC 2 H 3 O 2 6. (3 points) For the following reaction, assign oxidation numbers to all atoms (both reactants and products). Clearly show which substance is oxidized and which is reduced. 3 Cu (s) + 8 HNO 3(aq) 3 Cu(NO 3 ) 2(aq) + 2 NO (g) + 4 H 2 O (l) Cu: 0 This one gets oxidized. HNO 3 : H +1, N +5, O 2 This one gets reduced (the nitrogen). Cu(NO 3 ) 2 : Cu +2, N +5, O 2 NO: N +2, O 2 H 2 O: H +1, O 2 2
CHEM 10113, Quiz 3 September 28, 2011 Name (please print) All equations must be balanced and show phases for full credit. Significant figures count, show charges as appropriate, and please box your answers! IA Periodic Table of the Elements VIIIA (1) (18) 1 2 1 H IIA IIIA IVA VA VIA VIIA He 1.0080 (2) (13) (14) (15) (16) (17) 4.0026 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.9410 9.0122 10.811 12.011 14.007 15.999 18.998 20.179 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB........ VIIIB........ IB IIB Al Si P S Cl Ar 22.990 24.305 (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) 26.982 28.086 30.974 32.066 35.453 39.948 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.098 40.078 44.956 47.880 50.942 51.996 54.938 55.847 58.933 58.690 63.546 65.380 69.723 72.610 74.922 78.960 79.904 83.800 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.468 87.620 88.906 91.224 92.906 95.940 98.907 101.07 102.91 106.42 107.87 112.41 114.82 118.71 121.75 127.60 126.90 131.29 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.91 137.33 138.91 178.49 180.95 183.85 186.21 190.20 192.22 195.09 196.97 200.59 204.38 207.20 208.98 208.98 209.99 222.02 87 88 89 104 105 106 107 108 109 110 111 112 114 7 Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uug 223.02 226.03 227.03 (261) (262) (266) (264) (270) (268) (281) 1. (6 points) For the reaction between lead(ii) nitrate and ammonium sulfide, write the balanced molecular equation, ionic equation, and net ionic equation. Identify the precipitate and the spectator ions. a) molecular equation 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140.12 140.91 144.24 145.91 150.36 151.97 157.25 158.93 162.50 164.93 167.26 168.93 173.04 174.97 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232.04 231.04 238.03 237.05 244.06 243.06 247.07 247.07 242.06 252.08 257.10 258.10 259.10 260.11 Pb(NO 3 ) 2(aq) + (NH 4 ) 2 S (aq) Pb 2 S (s) + 2 NH 4 NO 3(aq) b) ionic equation Pb 2+ (aq) + 2 NO 3 (aq) + 2 NH 4 + (aq) + S (aq) Pb 2 S (s) + 2 NH 4 + (aq) + 2 NO 3 (aq) Precipitate is lead(ii) sulfide and the spectator ions are ammonium and nitrate ions. c) net ionic equation Pb 2+ (aq) + S (aq) Pb 2 S (s) 2. (2 points) You are given a solution that is 0.250 M in CuSO 4. If you dilute 8.00 ml of this solution to 15.0 ml, what is the concentration of the new solution? (0.250 M)(8.00 ml) = (15.0 ml)x x = 0.133 M 3
3. (4 points) SHOW ALL WORK. You have 1.024 g of an unknown diprotic acid. If 26.04 ml of 0.722 M NaOH is required to titrate the acid to the equivalence point, what is the formula mass of the acid? H 2 A (aq) + 2 NaOH (aq) 2 H 2 O (l) + Na 2 A (aq) 26.04 ml NaOH soln x (0.722 mol NaOH/1000 ml NaOH soln) x (1 mol H 2 A/2 mol NaOH) = 9.40044 x 10 3 mol H 2 A 1.024 g H 2 A/9.40044 x 10 3 mol H 2 A = 109 g/mol H 2 A 4. (6 points) For each of the following reactions, write the balanced molecular equation, or NR if there is no reaction. a) 2 HNO 3(aq) + CoCO 3(s) H 2 O (l) + CO 2(g) + Co(NO 3 ) 2(aq) b) Pb(NO 3 ) 2(aq) + 2 HCl (aq) PbCl 2(s) + 2 HNO 3(aq) c) K 2 CO 3(aq) + ZnCl 2(aq) 2 KCl (aq) + ZnCO 3(s) 5. (4 points) SHOW ALL WORK. For the following balanced reaction, Mg(C 2 H 3 O 2 ) 2(aq) + 2 KOH (aq) Mg(OH) 2(s) + KC 2 H 3 O 2(aq) if 54.6 ml of 7.54 M KOH is is fully consumed, and the final volume is 75.0 ml, what is the expected concentration of KC 2 H 3 O 2? 54.6 ml KOH soln x (7.54 mol KOH/1000 ml KOH soln) x (1 mol KC 2 H 3 O 2 /2 mol KOH) = 0.205842 mol KC 2 H 3 O 2 0.205842 mol KC 2 H 3 O 2 /0.0750 L soln = 2.74 M KC 2 H 3 O 2 6. (3 points) For the following reaction, assign oxidation numbers to all atoms (both reactants and products). Clearly show which substance is oxidized and which is reduced. 8 H + (aq) + 3 SO 3 (aq) + Cr 2 O 7 (aq) 3 SO 4 (aq) + 2 Cr 3+ (aq) + 4 H 2 O (l) H + : H +1 SO 3 : S +4, O 2 The sulfur gets oxidized. Cr 2 O 7 : Cr +6, O 2. The chromium gets reduced. SO 4 : S +6, O 2 Cr 3+ : Cr +3 H 2 O: H +1, O 2 4
CHEM 10113, Quiz 3 September 28, 2011 Name (please print) All equations must be balanced and show phases for full credit. Significant figures count, show charges as appropriate, and please box your answers! IA Periodic Table of the Elements VIIIA (1) (18) 1 2 1 H IIA IIIA IVA VA VIA VIIA He 1.0080 (2) (13) (14) (15) (16) (17) 4.0026 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.9410 9.0122 10.811 12.011 14.007 15.999 18.998 20.179 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB........ VIIIB........ IB IIB Al Si P S Cl Ar 22.990 24.305 (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) 26.982 28.086 30.974 32.066 35.453 39.948 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.098 40.078 44.956 47.880 50.942 51.996 54.938 55.847 58.933 58.690 63.546 65.380 69.723 72.610 74.922 78.960 79.904 83.800 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.468 87.620 88.906 91.224 92.906 95.940 98.907 101.07 102.91 106.42 107.87 112.41 114.82 118.71 121.75 127.60 126.90 131.29 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.91 137.33 138.91 178.49 180.95 183.85 186.21 190.20 192.22 195.09 196.97 200.59 204.38 207.20 208.98 208.98 209.99 222.02 87 88 89 104 105 106 107 108 109 110 111 112 114 7 Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uug 223.02 226.03 227.03 (261) (262) (266) (264) (270) (268) (281) 1. (6 points) For the reaction between sodium carbonate and copper(ii) chloride, write the balanced molecular equation, ionic equation, and net ionic equation. Identify the precipitate and the spectator ions. a) molecular equation 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140.12 140.91 144.24 145.91 150.36 151.97 157.25 158.93 162.50 164.93 167.26 168.93 173.04 174.97 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232.04 231.04 238.03 237.05 244.06 243.06 247.07 247.07 242.06 252.08 257.10 258.10 259.10 260.11 Na 2 CO 3(aq) + CuCl 2(aq) CuCO 3(s) + 2 NaCl (aq) b) ionic equation 2 Na + (aq) + CO 3 (aq) + Cu 2+ (aq) + 2 Cl (aq) CuCO 3(s) + 2 Na + (aq) + 2 Cl (aq) Precipitate is copper(ii) carbonate, and spectator ions are sodium and chloride. c) net ionic equation CO 3 (aq) + Cu 2+ (aq) CuCO 3(s) 2. (2 points) You are given a solution that is 0.350 M in CuSO 4. If you dilute 4.00 ml of this solution to 20.0 ml, what is the concentration of the new solution? (0.350 M)(4.00 ml) = (20.0 ml)x x = 0.0700 M 5
3. (4 points) SHOW ALL WORK. You have 0.853 g of an unknown triprotic acid. If 55.04 ml of 0.609 M NaOH is required to titrate the acid to the equivalence point, what is the formula mass of the acid? H 3 A (aq) + 3 NaOH (aq) 3 H 2 O (l) + Na 3 A (aq) 55.04 ml NaOH soln x (0.609 mol NaOH/1000 ml NaOH soln) x (1 mol H 3 A/3 mol NaOH) = 0.01117312 mol H 3 A 0.853 g H 3 A/0.01117312 mol H 3 A = 76.3 g/mol H 3 A 4. (6 points) For each of the following reactions, write the balanced molecular equation, or NR if there is no reaction. a) K 2 CO 3(aq) + Cu(NO 3 ) 2(aq) 2 KNO 3(aq) + CuCO 3(s) b) Fe(OH) 3(s) + 3 HNO 3(aq) 3 H 2 O (l) + Fe(NO 3 ) 3(aq) c) FeSO 3(s) + 2 HNO 3(aq) H 2 O (l) + SO 2(g) + Fe(NO 3 ) 2(aq) 5. (4 points) SHOW ALL WORK. For the following balanced reaction, Mg(C 2 H 3 O 2 ) 2(aq) + 2 KOH (aq) Mg(OH) 2(s) + KC 2 H 3 O 2(aq) if 42.4 ml of 2.10 M KOH is fully consumed, and the final volume is 57.5 ml, what is the expected concentration of KC 2 H 3 O 2? 42.4 ml KOH soln x (2.10 mol KOH/1000 ml KOH soln) x (1 mol KC 2 H 3 O 2 /2 mol KOH) = 0.04452 mol KC 2 H 3 O 2 0.04452 mol KC 2 H 3 O 2 /0.0575 L soln = 0.774 M KC 2 H 3 O 2 6. (3 points) For the following reaction, assign oxidation numbers to all atoms (both reactants and products). Clearly show which substance is oxidized and which is reduced. 5 H 2 O (l) + 4 Cl 2(g) + S 2 O 3 (aq) 2 SO 4 (aq) + 8 Cl (aq) + 10 H + (aq) H 2 O: H +1, O 2 Cl 2 : Cl 0. The Cl gets reduced. S 2 O 3 : S +2, O 2. The S gets oxidized. SO 4 : S +6, O 2 Cl : Cl 1 H + : H +1 6