(please print) (1) (18) H IIA IIIA IVA VA VIA VIIA He (2) (13) (14) (15) (16) (17)

Transcription

1 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) H IIA IIIA IVA VA VIA VIIA He (2) (13) (14) (15) (16) (17) Li Be B C N O F Ne Na Mg IIIB IVB VB VIB VIIB VIIIB IB IIB Al Si P S Cl Ar (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uug (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 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 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 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 = M 1

2 3. (4 points) SHOW ALL WORK. You have g of an unknown diprotic acid. If ml of 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) ml NaOH soln x (0.509 mol NaOH/1000 ml NaOH soln) x (1 mol H 2 A/2 mol NaOH) = x 10 3 mol H 2 A g H 2 A/ 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) = mol KC 2 H 3 O mol KC 2 H 3 O 2 / L soln = 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

3 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) H IIA IIIA IVA VA VIA VIIA He (2) (13) (14) (15) (16) (17) Li Be B C N O F Ne Na Mg IIIB IVB VB VIB VIIB VIIIB IB IIB Al Si P S Cl Ar (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uug (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 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 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 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 = M 3

4 3. (4 points) SHOW ALL WORK. You have g of an unknown diprotic acid. If ml of 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) ml NaOH soln x (0.722 mol NaOH/1000 ml NaOH soln) x (1 mol H 2 A/2 mol NaOH) = x 10 3 mol H 2 A g H 2 A/ 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) = mol KC 2 H 3 O mol KC 2 H 3 O 2 / 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

5 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) H IIA IIIA IVA VA VIA VIIA He (2) (13) (14) (15) (16) (17) Li Be B C N O F Ne Na Mg IIIB IVB VB VIB VIIB VIIIB IB IIB Al Si P S Cl Ar (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Uuu Uub Uug (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 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 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 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 = M 5

6 3. (4 points) SHOW ALL WORK. You have g of an unknown triprotic acid. If ml of 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) ml NaOH soln x (0.609 mol NaOH/1000 ml NaOH soln) x (1 mol H 3 A/3 mol NaOH) = mol H 3 A g H 3 A/ 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) = mol KC 2 H 3 O mol KC 2 H 3 O 2 / L soln = 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