BALANCING REDOX EQUATIONS EXERCISE

Size: px
Start display at page:

Download "BALANCING REDOX EQUATIONS EXERCISE"

Transcription

1 Ag + NO3 Ag 1+ + NO N2H4 + H2O2 N2 + H2O CO + Fe2O3 FeO + CO NO3 + CO CO2 + NO H2 + Fe3O4 Fe + H2O 0 +8/ BALANCING REDOX EQUATIONS EXERCISE H2C2O4 + MnO4 CO2 + MnO Zn + NO3 Zn 2+ + NO C2N2 CN + CNO ClO2 + SbO2 ClO2 + Sb(OH) (1) Cr2O7 2 + I Cr 3+ + I

2 Fe3O4 + H2O2 Fe 3+ + H2O +8/ MnO4 + NH3 MnO2 + NO CN + CrO4 2 CNO + Cr(OH) (1) Fe(CN)6 3 + Cr2O3 Fe(CN)6 4 + CrO (1) (1) NH4NO3 N2O NO2 + MnO4 NO3 + Mn2+ (in acid solution) I + MnO4 I2 + MnO2 (in basic solution) Cl2 + S2O3 2 Cl + SO4 2 (in acidic solution) CH4 + O2 C + H2O Br2 Br + BrO3 (in basic solution)

3 BALANCING REDOX EQUATIONS EXERCISE 1. Ag + NO3 Ag 1+ + NO ox: 3 (Ag Ag e ) 0 +1 red: NO3 + 3 e NO Ag + NO3 3 Ag 1+ + NO 3 Ag + NO3 + 4 H + 3 Ag 1+ + NO + 2 H2O 2. N2H4 + H2O2 N2 + H2O ox: N2H4 N2 + 4 e 2 0 red: 2 (H2O2 + 2 e 2 H2O) 1 2 N2H4 + 2 H2O2 N2 + 4 H2O 3. CO + Fe2O3 FeO + CO ox: CO CO2 + 2 e 2 +4 red: Fe2O3 + 2 e 2 FeO CO + Fe2O3 2 FeO + CO2 4. NO3 + CO CO2 + NO ox: CO CO2 + 2 e red: 2 (NO3 + 1 e NO2) NO3 + CO CO2 + 2 NO2 2 NO3 + CO + 2 H + CO2 + 2 NO2 + H2O

4 5. H2 + Fe3O4 Fe + H2O 0 +8/ ox: 4 (H2 H2O + 2 e ) 0 +1 red: Fe3O4 + 8 e 3 Fe +8/3 0 4 H2 + Fe3O4 3 Fe + 4 H2O 6. H2C2O4 + MnO4 CO2 + MnO ox: 5 (H2C2O4 2 CO2 + 2 e ) red: 2 (MnO4 + 5 e MnO) H2C2O4 + 2 MnO4 10 CO2 + 2 MnO 5 H2C2O4 + 2 MnO4 + 2 H + 10 CO2 + 2 MnO + 6 H2O 7. Zn + NO3 Zn 2+ + NO ox: 3 (Zn Zn e ) 0 +2 red: 2 (NO3 + 3 e NO) Zn + 2 NO3 3 Zn NO 3 Zn + 2 NO3 + 8 H + 3 Zn NO + 4 H2O 8. C2N2 CN + CNO ox: C2N2 2 CNO + 2e red: C2N2 + 2e 2 CN C2N2 2 CN + 2 CNO C2N2 + H2O CN + CNO + 2 H +

5 9. ClO2 + SbO2 ClO2 + Sb(OH) (1) ox: SbO2 Sb(OH)6 + 2e +3 red: 2 (ClO2 + 1 e ClO2 ) ClO2 + SbO2 2 ClO2 + Sb(OH)6 2 ClO2 + SbO2 + 2 OH + 2 H2O 2 ClO2 + Sb(OH)6 10. Cr2O7 2 + I Cr 3+ + I ox: 3 (2 I I2 + 2e ) 1 0 red: Cr2O e 2 Cr Cr2O I 2 Cr I2 Cr2O I + 14 H + 2 Cr I2 + 7 H2O 11. Fe3O4 + H2O2 Fe 3+ + H2O +8/ ox: 2 (Fe3O4 3 Fe e ) +8/3 +3 red: H2O2 + 2 e 2 H2O Fe3O4 + H2O2 6 Fe H2O 2 Fe3O4 + H2O H + 6 Fe H2O 12. MnO4 + NH3 MnO2 + NO ox: 3 (NH3 NO3 + 8e ) 3 +5 red: 8 ( MnO4 + 3 e MnO2) MnO4 + 3 NH3 8 MnO2 + 3 NO3 8 MnO4 + 3 NH3 + 5 H + 8 MnO2 + 3 NO3 + 7 H 2 O

6 13. CN + CrO4 2 CNO + Cr(OH) (1) ox: 3 (CN CNO + 2 e ) red: 2 (CrO e Cr(OH)3) CN + 2 CrO H 2 O 3 CNO + 2 Cr(OH)3 + 4 OH 3 CN + 2 CrO H 2 O 3 CNO + 2 Cr(OH)3 + 4 OH 14. Fe(CN)6 3 + Cr2O3 Fe(CN)6 4 + CrO (1) (1) +6 2 ox: Cr2O3 2 CrO e red: 6 (Fe(CN) e Fe(CN)6 4 ) Fe(CN)6 3 + Cr2O3 + 5 H 2 O 6 Fe(CN) CrO H + 6 Fe(CN)6 3 + Cr2O3 + 5 H 2 O 6 Fe(CN) CrO H NH4NO3 N2O ox: 2 NH4 + N2O + 8e 3 +1 red: 2 NO3 + 8 e N2O NH NO3 2 N2O NH4NO3 N2O + 2 H2O 16. NO 2 + MnO 4 NO3 + Mn 2+ (in acid solution) ox: 5 (NO 2 NO3 + 2 e ) red: 2 (MnO e Mn 2+) NO MnO H + 5 NO Mn H 2 O 5 NO MnO H + 5 NO Mn H 2 O

7 17. I + MnO 4 I 2 + MnO 2 (in basic solution) ox: 3 (2 I I2 + 2 e ) 1 0 red: 2 (MnO e MnO 2 ) I + 2 MnO 4 3 I MnO 2 6 I + 2 MnO H 2 O 3 I MnO OH 18. Cl2 + S2O3 2 Cl + SO4 2 (in acidic solution) ox: S2O3 2 2 SO e red: 4 (Cl2 + 2 e 2 Cl ) Cl2 + S2O H2O 8 Cl + 2 SO H + 4 Cl2 + S2O H2O 8 Cl + 2 SO H CH4 + O2 C + H2O ox: CH4 C + 4 e 4 0 red: O e 2 H 2 O 0 2 CH4 + O2 CH4 + O2 C C + 2 H2O 20. Br2 Br + BrO3 (in basic solution) ox: Br2 2 BrO e 0 +5 red: 5 (Br2 + 2 e 2 Br ) Br2 10 Br + 2 BrO3 3 Br2 + 6 OH 5 Br + BrO3 + 3 H2O

8 Predicting REDOX Reactions Building a REDOX Table 1. The following reactions were performed. Construct a table of relative strengths of oxidizing and reducing agents written as reductions and with the SOA to WOA. Zn + Co 2+ Zn 2+ + Co Mg 2+ + Zn no rxn Half rxns: Final Order: Zn e Zn SOA Co e Co X Co e Co Zn e Zn Mg e Mg Mg e Mg SRA 2. In a school laboratory four metals were combined with each of four solutions. Construct a table of relative strengths of oxidizing and reducing agents written as reductions and with the SOA to WOA. Be + Cd 2+ Be 2+ + Cd Cd + 2 H + Cd 2+ + H 2 Ca 2+ + Be no rxn Cu + 2 H + no rxn Half rxns: Final Order: Be e Be SOA Cu e Cu X Cd e Cd 2 H + + 2e H 2 X 2 H+ + 2e H 2 Cd2+ + 2e Cd Ca e Ca Be e Be X Cu e Cu Ca e Ca SRA 3. Write and rank the two half reaction equations for each of the following reactions: (a) Co + Cu(NO 3 ) 2 Cu + Co(NO 3 ) 2 Cu e Cu Co e Co

9 (b) Cd + Zn(NO 3 ) 2 Zn + Cd(NO 3 ) 2 Zn e Zn Cd e Cd (c) Br 2 + 2KI I KBr Br 2 + 2e 2 Br I 2 + 2e 2 I 4. Prepare a REDOX table of halfreactions showing the relative strengths of oxidizing and reducing agent for the following: OA Al 3+ Tl + Ga 2+ In 3+ RA Al X Tl X X X X Ga X X In X X X WOA Rank 4 th SOA Rank 1 st Rank 3 rd Rank 2 nd SOA Tl + + e Tl In e In Ga e Ga Al e Al SRA Prediction REDOX Reaction in Solution 1. List all the entities initially present in the following mixtures and identify all possible oxidizing and reducing agents. Write the resulting REDOX reaction (or no rxn). (a) A lead strip is placed in a copper (II) sulfate solution. OA (Cu +, Cu) (not in H + ) (H2) Pb SRA Cu 2+ SOA SO4 H2O RA (Pb 2+ ) (S2O8 2 ) (O2) ox: Pb Pb e red: Cu e Cu Pb + Cu 2+ Pb 2+ + Cu

10 (b) A potassium dichromate solution is added to an acidic iron (II) nitrate solution. OA (K) (Cr 3+ ) (Fe) (NO2) (H2) K + Cr2O7 2 SOA Fe 2+ SRA H +, NO3 H2O RA (Fe 3+ ) (O2) 6x ox: 6 Fe 2+ 6 Fe e red: Cr2O e 2 Cr 3+ Cr2O Fe H + 2 Cr Fe H2O (c) An aqueous chlorine solution is added to a phosphorous acid solution. OA (Cl ) RA (H2) Cl2 SOA H +, PO3 3 H2O SRA (O2) ox: 2 H2O O2 + 4 H e 2x red: 2 Cl2 + 4 e 4 Cl 2 Cl2 + 2 H2O 4 Cl + O2 + 4 H + (d) A potassium permanganate solution is mixed with an acidified tin (II) chloride solution. OA (K) (Mn 2+ ) (Sn) (H2) K + MnO4, H + SOA Sn 2+ SRA Cl H2O RA (Sn 4+ ) (Cl2) (O2) 5x ox: 5 Sn 2+ 5 Sn e 2x red: 2 MnO e 2 Mn 2+ 2 MnO4 + 5 Sn H + 2 Mn Sn H2O

11 Electrochemical (Galvanic or Voltaic) Cells Worksheet 1. a) Determine the anode, cathode and calculate the standard cell potential produced by a galvanic cell consisting of a Ni electrode in contact with a solution of Ni 2+ ions and a Ag electrode in contact with a solution of Ag 1+ ions. Ni 2+ (aq) + 2e Ni (s) E = 0.26 V (lesser flip) Ag + (aq) + e Ag (s) E = V ANODE: Ni (s) Ni 2+ (aq) + 2e E = V CATHODE: 2 Ag + (aq) + 2e 2 Ag (s) b) Write the shorthand cell notation. Ni (s) Ni 2+ (aq) Ag 1+ (aq) Ag (s) E = V E = V 2. a) Determine the anode, cathode and calculate the voltage produced by a galvanic cell consisting of an Fe electrode in contact with a solution of Fe 2+ ions and a Al electrode in contact with a solution of Al 3+ ions. Fe 2+ (aq) + 2e Fe (s) Al 3+ (aq) + 3e Al (s) E = 0.44 V E = 1.66 V (lesser flip) ANODE: 2 Al (s) 2 Al 3+ (aq) + 6e E = V CATHODE: 3 Fe 2+ (aq) + 6e 3 Fe (s) b) Write the shorthand cell notation. Al (s) Al 3+ (aq) Fe 2+ (aq) Fe (s) E = 0.44 V E = V 3. a) Determine the anode, cathode and calculate standard cell potential produced by a galvanic cell consisting of a C electrode in contact with an acidic solution of ClO 4 ions and a Cu electrode in contact with a solution of Cu 2+ ions. Which is anode and which is the cathode? ClO 4 (aq) + 8H + (aq) + 8e Cl (aq) + 4H 2 O (l) Cu 2+ (aq) + 2e Cu (s) E = V E = V (lesser flip) ANODE: 4 Cu (s 8 Cu 2+ (aq) ) + 8e E = 0.34 V CATHODE: ClO 4 (aq) + 8H + (aq) + 8e Cl (aq) + 4H 2 O (l) b) Write the shorthand cell notation. Cu (s) Cu 2+ (aq) ClO 4, H + (aq) C (s) E = V E = V

12 4. An electrochemical cell is constructed using electrodes based on the following half reactions: Pb 2+ (aq) + 2e Pb (s) Au 3+ (aq) + 3e Au (s) a) Which is the anode and which is the cathode in this cell? ANODE: Pb CATHODE: Au b) What is the standard cell potential? ANODE: 3 Pb (s) 3 Pb 2+ (aq) + 6e E = V CATHODE: 2 Au 3+ (aq) + 6e 2 Au (s) E = V E = V 5. Use complete halfreactions and potentials to predict whether the following reactions are spontaneous or nonspontaneous in aqueous solutions. If the cell is spontaneous, write the cell shorthand notation. a) Ca 2+ (aq) + 2 I (aq) Ca (s) + I 2(aq) ANODE: 2 I (aq) I 2(aq) + 2e E = 0.54 V CATHODE: Ca 2+ (aq) + 2e Ca (s) E = 2.87 V E = 3.41 V E is negative, therefore the cell is nonspontaneous. b) 2 H 2 S (g) + O 2(g) 2 H 2 O (l) + 2 S (s) ANODE: H 2 S (g) 2 S (s) + 2H + (aq) + 2e E = 0.14 V CATHODE: O 2(g) + 4H + (aq) + 4e 2 H 2 O (l) E = V E = V E is positive, therefore the cell is spontaneous. Pt (s) H 2 S (g) ; S (g) O 2 (g), H + (aq) C (s) c) SO 2(g) + MnO 2(s) Mn 2+ (aq) + SO 4 2 (aq) ANODE: SO 2(g) + 2 H 2 O (l) SO 4 2 (aq) + 4H + (aq) + 2e E = 0.18 V CATHODE: MnO 2(s) + 4H + (aq) + 2e Mn 2+ (aq) + 2 H 2 O (l) E is positive, therefore the cell is spontaneous. Pt (s) SO 2(g) ; SO 4 2 (aq) MnO 2(s), H + (aq) ; Mn2+ (aq) C (s) E = V E = V d) 2 H + (aq) + 2 Br (aq) H 2(g) + Br 2(aq) ANODE: 2 Br (aq) Br 2(l) + 2e E = 1.07 V CATHODE: 2 H + (aq) + 2e H 2(g) E = 0.00 V E = 1.07 V E is negative, therefore the cell is nonspontaneous.

13 e) Ce 4+ (aq) + Fe2+ (aq) Ce3+ (aq) + Fe3+ (aq) ANODE: Fe 2+ (aq) Fe3+ (aq) + e E = 0.77 V CATHODE: Ce 4+ (aq) + e Ce 3+ (aq) E = V E = 2.38 V E is negative, therefore the cell is nonspontaneous. f) Cr 2+ (aq) + Cu2+ (aq) Cr3+ (aq) + Cu+ (aq) ANODE: Cr 2+ (aq) Cr3+ (aq) + e E = V CATHODE: Cu 2+ (aq) + e Cu + (aq) E = V E = V E is positive, therefore the cell is spontaneous. C (s) Cr 2+ (aq) ; Cr 3+ (aq) Cu 2+ (aq) ; Cu + (aq) C (s)

14 Electrolytic Cells Worksheet 1. a) Give the cathode, anode and overall equations including cell potentials to conclude what happens to the ph of the solution near the cathode and anode during the electrolysis of KNO 3? Consider all possible reactions. OA K (2.92) H 2 (0.83) K + NO 3 SRA H 2 O SOA RA O 2 (1.23) ox: 2 H 2 O O 2 + 4H e E ox = 1.23 V 2x red: 2 H 2 O + 4 e 2H 2 + 2OH E red = 0.83 V 6 H 2 O O 2 + 2H 2 + 4H OH E cell = 2.06 V 2 H 2 O O 2 + 2H 2 E cell = 2.06 V at the anode ph, at the cathode ph b) Write the shorthand cell notation. C(s) C(s) or Pt(s) KNO 3(aq) or Pt(s) 2. Given the following molten systems, predict the products at each electrode. Assume inert electrodes and sufficient voltage to cause a reaction to take place. Consider all possible rxns. a) FeBr 2 OA Fe (0.45) SRA Fe 2+ SOA Br RA Fe 3+ (0.77) Br 2 (1.07) Fe 3+ is produced at the anode, Fe at the cathode. b) NiCl 2 OA RA Ni (0.26) Ni 2+ SOA Cl SRA Cl 2 (1.36) Cl 2 is produced at the anode, Ni at the cathode.

15 c) Na 2 SO 4 OA Na (2.71) Na + SOA SO 4 2 SRA RA S 2 O 4 2 (2.01) S 2 O 4 2 is produced at the anode, Na at the cathode. 3. Given the following 1.00 M solutions at 25 C predict the anode and cathode half cell reactions. What is the minimum voltage required for each cell to operate? a) LiMnO 4 OA Li (3.00) MnO 2 (+0.60) H 2 (0.83) Li + MnO 4 SOA H 2 O SRA RA O 2 (1.23) E cell = V = 0.63 V ; 0.63 V are needed b) CrI 3 OA Cr (0.76), Cr 2+ (0.41) H 2 (0.83) Cr 3+ SOA I SRA H 2 O SRA RA I 2 (0.54) O 2 (1.23) E cell = V = 0.95 V ; 0.95 V are needed c) Sn(NO 3 ) 2 OA Sn (0.14) H 2 (0.83) SRA Sn2+ SOA NO 3 H 2 O SRA RA Sn 4+ (0.15) O 2 (1.23) E cell = V = 0.29 V ; 0.29 V are needed d) Ag 2 SO 4 OA Ag (+0.80) SO 2 3 (0.93) H2 (0.83) Ag + SOA SO 2 4 H 2 O SRA RA S 2 O 2 8 (2.01) O2 (1.23) E cell = V = 0.43 V ; 0.43 V are needed

16 Stoichiometry and Free Energy Worksheet 1. How many coulombs, q, are required to deposit g of Ni from a solution of Ni 2+? Ni e Ni m = g M = g/mol n q q F then q n e e 1mol Ni g x g 1930C 1.93x 10 x F 3 x 1mol Cu C 2 mol e 2 x 9.65 x 10 mol e 4 C 2. Three electrolysis cells are connected in series. They contain, respectively, solutions of copper (II) nitrate, silver nitrate, and chromium (III) sulfate. If 1.00 g of copper is electrochemically deposited in the first cell, calculate the mass of silver and chromium deposited in the other cells. 1) Cu e Cu m = 1.00 g M = g/mol n e (Cu) 1.00g x 1mol Cu 63.55g 2 mol e x 1mol Cu mol 2) Ag + + e Ag n = mol m =? M = g/mol m Ag mol e 1mol Ag x 1mol e g x 1mol Ag 3.40g 3) Cr e Cr n = mol m =? M = g/mol mcr 1mol Cr mol e x 3 mol e g x 1mol Cr g

17 3. A constant current of 3.7 milliampere is passed through molten sodium chloride for 9.0 minutes. The sodium produced is allowed to react with water (500 ml). What is the ph of the resulting solution? Na + + e Na I = 3.7 ma n =? t = 9.0 min = 540 s n Na 3.7 x 10 s 2.1x C x 540s x mol mol e 9.65x 10 4 C 1mol Na x 1mol e 2 Na + 2 H 2 O 2 NaOH + H 2 n = 2.1 x 10 5 mol C =? V = 0.500L C NaOH ph 14 log (4.2 x x x mol NaOH mol x x 2 mol Na M 5 ) L 4. Given these halfreactions and their standard reduction potentials. 2 ClO H e Cl H 2 O E o (ClO 4 ) = V S 2 O e 2 SO 4 2 E o (S 2 O 8 2 ) = V Calculate: (a) Complete the REDOX reaction. an (ox): Cl H 2 O 2 ClO H e E o = 1.47 V 5 x cat (red): 5 S 2 O e 10 SO 4 2 E o = V 5 S 2 O Cl H 2 O 10 SO ClO H + (b) E o cell = V = V (b) ΔG o for the cell reaction G o = n F E o cell 10 mol e 9.65 x 10 4 C 0.54 J x x J 520 kj mol e C

18 (c) K eq for the cell reaction. ln Keq Keq J mol RT G J mol 1 K 1 x 298 K ( ) e RT G e ((210)) 1.6 x The system 2 AgI + Sn Sn Ag + I has a calculated E o cell = V. What is the value of K eq for this system? ln Keq Keq nfe o RT cell ( e nfe RT cell 2 mol e x 9.65 x 10 4 C x J C J mol 1 K 1 x 298 K ) e (1.2) Calculate ΔG o for the following reaction, given that its standard cell potential is V at 25 o C. NiO Cl + 4 H + Cl 2 + Ni H 2 O G o = n F E o cell 2 mol e 9.65 x 10 4 C J x x J 67.6 kj mol e C

19 Review Questions for SCH 4U Electrochemistry Test 1. Balance the following REDOX reaction in acidic solution Zn + NO 3 Zn 2+ + NH ox: 4 (Zn Zn e ) 0 +2 red: NO3 + 8 e NH Zn + NO 3 4 Zn + NO 3 4 Zn 2+ + NH H + 4 Zn 2+ + NH H 2 O 2. Balance the following REDOX reaction in acidic solution MnO4 + C2 O 4 2 CO2 + MnO ox: 3 (C 2 O CO2 + 2 e ) red: 2 (MnO e MnO 2 ) MnO 4 2 MnO C 2 O C 2 O MnO CO H + 2 MnO CO H 2 O 3. Given the following reactions, generate a standard reduction potential table: W 2+ + Z Z 2+ + W X 2+ + W W 2+ + X X 2+ + Y no rxn SOA Y e Y X e X W e W Z e Z SRA 4. Describe and explain what will happen if carbon electrodes are placed in a FeCl 2 solution. Give ALL possible half reactions. Species in Solution: Fe 2+ Cl 1 H 2 O Possible Reduction Half Reactions (OA): Fe e Fe E o = 0.44 V SOA 2 H 2 O + 2e O 2 + 4H + + 4e E o = 0.83 V

20 Possible Oxidation Half Reactions (RA): 2 Cl 1 Cl 2 + 2e E o = 1.36 V Fe 2+ Fe 3+ + e E o = 0.77 V SRA 2 H 2 O O 2 + 4H + + 4e E o = 1.23 V Full Reaction: 3 Fe 2+ Fe + 2 Fe 3+ E o cell = 1.21 V 5. Use the redox spontaneity rule to predict whether the following mixtures will be spontaneous or not. (a) Nickel metal in a solution of silver ions OA Ag (+0.80) H 2 (0.83) Ni SRA Ag + SOA H 2 O RA Ni 2+ (+0.26) O 2 (1.23) E o cell = V V = V spontaneous (b) Chlorine gas bubbled into a bromide ion solution OA Cl (+1.36) H 2 (0.83) Cl 2 SOA Br SRA H 2 O RA Br 2 (1.07) O 2 (1.23) E o cell = V 1.07 V = V spontaneous (c) Copper metal in nitric acid OA NO 2 (+0.80) H 2 (0.83) Cu SRA NO 3, H + SRA H 2 O RA Cu + (0.52) (1.07) O 2 (1.23) Cu 2+ (0.34) E o cell = V 0.34 V = V spontaneous 6. Three electrolysis cells are connected in series. They contain, respectively, solutions of zinc nitrate, aluminum nitrate and silver nitrate. If 1.00 g of silver is deposited in the third cell what mass of aluminum and zinc were deposited in the other cells. 1) Ag + + e Ag m = 1.00 g M = g/mol

21 ne 1.00 g x 1mol Ag g 1mol e x 1mol Ag 9.27 x 10 3 mol 2) Zn e Zn n = 9.27 x 10 3 mol m =? M = g/mol mzn 1mol Zn g 9.27 x 10 3 mol x x g 2 mol e 1mol Zn 3) Al e Al n = 9.27 x 10 3 mol m =? M = g/mol mal 7. For the cell: 1mol Al g 9.27 x 10 3 mol x x g 3 mol e 1mol Zn Ag (s) Ag1+ (aq) Zn2+ (aq) C (s) a) List all possible halfreactions that will occur at the cathode, including their cell potentials. Zn e Zn E o = 0.76 V SOA 2 H2O + 2 e 2 OH 1 + H2 E o = 0.83 V b) List the possible halfreactions that will occur at the anode, including their cell potentials. Ag Ag 1+ + e E o = 0.80 V SRA 2 H 2 O O 2 + 4H + + 4e E o = 1.23 V c) Give the full balanced REDOX reaction with the value for the cell s E o Zn 2+ + Ag Zn + Ag 1+ d) Draw a fully labeled diagram of the electrolytic cell. E o cell = 0.80 V (+0.76V) = 1.56 V

22 8. For the cell: Ag (s) S2 (aq) HCl (aq) Pt (s) a) List all the possible anode reactions with their E o values. 2 Ag + S 2 Ag 2 S E o = V SRA 2 H 2 O O 2 + 4H + + 4e E o = 1.23 V b) List all the possible cathode reactions with their E o values. 2 H2O + 2 e 2 OH 1 + H2 E o = 0.83 V 2 H + + 2e H 2 E o = 0.00 V SOA c) Give the most probable reaction for the electrochemical cell and the value for the cell s E o 2 Ag + S H + Ag 2 S + H 2 E o cell = V d) Draw a fully labeled diagram of the cell. e) As this reaction proceeds, what will happen to the E o value? Voltage will decrease because concentration of reactants is decreasing over time. f) What would happen if HCl(aq) was added to the cathodic halfcell? If HCl was added, then [H+] would increase, shifting the half reaction to the products.

(5) Balance each Redox equation using the half reaction method. Identify the oxidizing agent and the reducing agent. (a) Zn + Ag + Zn 2+ + Ag

(5) Balance each Redox equation using the half reaction method. Identify the oxidizing agent and the reducing agent. (a) Zn + Ag + Zn 2+ + Ag Oxidation Numbers and Redox Reactions (1) Assign oxidation numbers to each element in the following compounds/ions. Name: Period: (a) HNO 3 (i) CO 2 + (b) NH 4 + (j) N 2 H 5 2- (c) CrO 4 (k) H 4 P 2 O

More information

Electrochemistry - ANSWERS

Electrochemistry - ANSWERS Electrochemistry - ANSWERS 1. Using a table of standard electrode potentials, predict if the following reactions will occur spontaneously as written. a) Al 3+ + Ni Ni 2+ + Al Al 3+ + 3e - Al E = -1.68

More information

CHEM N-12 November In the electrolytic production of Al, what mass of Al can be deposited in 2.00 hours by a current of 1.8 A?

CHEM N-12 November In the electrolytic production of Al, what mass of Al can be deposited in 2.00 hours by a current of 1.8 A? CHEM161 014-N-1 November 014 In the electrolytic production of Al, what mass of Al can be deposited in.00 hours by a current of 1.8 A? The number of moles of electrons passed in.00 hours by a current of

More information

Electrochemistry HW. PSI Chemistry

Electrochemistry HW. PSI Chemistry Electrochemistry HW PSI Chemistry Name Multiple choice questions: I. Oxidation numbers and half-reactions 1) What is the oxidation number of potassium in KMnO4? A) 0 B) +1 C) +2 D) -1 E) +3 2) What is

More information

A. Oxidation involves loss of electrons and a decrease in oxidation state. B. Oxidation involves gain of electrons and an increase in oxidation state.

A. Oxidation involves loss of electrons and a decrease in oxidation state. B. Oxidation involves gain of electrons and an increase in oxidation state. 1. Which statement is correct? A. Oxidation involves loss of electrons and a decrease in oxidation state. B. Oxidation involves gain of electrons and an increase in oxidation state. C. Reduction involves

More information

Chemistry 30 - Electrochemistry Part B Unit Exam

Chemistry 30 - Electrochemistry Part B Unit Exam Chemistry 30 - Electrochemistry Part B Unit Exam VERSION NUMBER: 1 Name: Numeric Response Instructions: Record your answer by writing it in the boxes and then filling in the corresponding circles. If an

More information

K + Cl - Metal M. Zinc 1.0 M M(NO

K + Cl - Metal M. Zinc 1.0 M M(NO Redox and Electrochemistry This section should be fresh in your minds because we just did this section in the text. Closely related to electrochemistry is redox chemistry. Count on at least one question

More information

Chem 1721 Brief Notes: Chapter 19

Chem 1721 Brief Notes: Chapter 19 Chem 1721 Brief Notes: Chapter 19 Chapter 19: Electrochemistry Consider the same redox reaction set up 2 different ways: Cu metal in a solution of AgNO 3 Cu Cu salt bridge electrically conducting wire

More information

1332 CHAPTER 18 Sample Questions

1332 CHAPTER 18 Sample Questions 1332 CHAPTER 18 Sample Questions Couple E 0 Couple E 0 Br 2 (l) + 2e 2Br (aq) +1.06 V AuCl 4 + 3e Au + 4Cl +1.00 V Ag + + e Ag +0.80 V Hg 2+ 2 + 2e 2 Hg +0.79 V Fe 3+ (aq) + e Fe 2+ (aq) +0.77 V Cu 2+

More information

Chapter 16 Oxidation-Reduction Reactions and Electrochemistry Section Review 16.1

Chapter 16 Oxidation-Reduction Reactions and Electrochemistry Section Review 16.1 Name Date Chemistry Precision and Design Chapter 16 Oxidation-Reduction Reactions and Electrochemistry Section Review 16.1 Concept Review 1. What is a redox reaction? 2. Compare and contrast oxidation

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) is reduced in the following reaction: 1) Cr2O7 2- + 6S2O3 2- + 14H+ 2Cr3+ + 3S4O6 2-

More information

2. Write the chemical formula(s) of the product(s) and balance the following spontaneous reactions.

2. Write the chemical formula(s) of the product(s) and balance the following spontaneous reactions. 1. Using the Activity Series on the Useful Information pages of the exam write the chemical formula(s) of the product(s) and balance the following reactions. Identify all products phases as either (g)as,

More information

V. Electrochemistry. Oxidation Numbers oxidation number: the apparent charge of an atom in a compound/ion if all bonds are considered to be ionic.

V. Electrochemistry. Oxidation Numbers oxidation number: the apparent charge of an atom in a compound/ion if all bonds are considered to be ionic. V. Electrochemistry Electrochemistry is the branch of chemistry that deals with reactions that involve the transfer of electrons and allow for the interconversion between chemical and electrical energy.

More information

Test #4 Last Name First Name Zumdahl, Chapter 17 and Section November 24, Reduction Potentials at 25 C E (V) E (V)

Test #4 Last Name First Name Zumdahl, Chapter 17 and Section November 24, Reduction Potentials at 25 C E (V) E (V) Form S Chemistry 1442/1302 Name (please print) Test #4 Last Name First Name Zumdahl, Chapter 17 and Section 4.9-4.10 November 24, 2004 Reduction Potentials at 25 C E (V) E (V) F 2 (g) + 2 e 2 F (aq) 2.87

More information

Chapter 13: Electrochemistry. Electrochemistry. The study of the interchange of chemical and electrical energy.

Chapter 13: Electrochemistry. Electrochemistry. The study of the interchange of chemical and electrical energy. Chapter 13: Electrochemistry Redox Reactions Galvanic Cells Cell Potentials Cell Potentials and Equilbrium Batteries Electrolysis Electrolysis and Stoichiometry Corrosion Prevention Electrochemistry The

More information

Chemistry of Voltaic Cells

Chemistry of Voltaic Cells Chemistry of Voltaic Cells An electrochemical cell consists of two parts, called half-cells, in which the separate oxidation and reduction reactions take place. Each half cell contains a metal electrode

More information

Electrochemistry. Chapter 17 Electrochemistry GCC CHM152. Ox # examples. Redox: LEO the lion goes GER. Oxidation Numbers (Chapter 4).

Electrochemistry. Chapter 17 Electrochemistry GCC CHM152. Ox # examples. Redox: LEO the lion goes GER. Oxidation Numbers (Chapter 4). Chapter 17 Electrochemistry GCC CHM152 Electrochemistry Electrochemistry is the study of batteries and the conversion between chemical and electrical energy. Based on redox (oxidation-reduction) reactions

More information

38. Consider the following reaction that occurs in a breathalyzer: 2Cr 2 O 7

38. Consider the following reaction that occurs in a breathalyzer: 2Cr 2 O 7 Electrochemistry Multiple Choice January 1999 37. Consider the following redox reaction: 2MnO 4 - + 3ClO 3 - + H 2 O 3ClO 4 - + 2MnO 2 + 2OH - The reducing agent is A. H 2 O B. ClO 3 - C. MnO 2 D. MnO

More information

Name AP CHEM / / Collected Essays Chapter 17 Answers

Name AP CHEM / / Collected Essays Chapter 17 Answers Name AP CHEM / / Collected Essays Chapter 17 Answers 1980 - #2 M(s) + Cu 2+ (aq) M 2+ (aq) + Cu(s) For the reaction above, E = 0.740 volt at 25 C. (a) Determine the standard electrode potential for the

More information

Redox and Electrochemistry

Redox and Electrochemistry Redox and Electrochemistry Oxidation: Historically means the combination of a substance with oxygen 2Mg + O 2 2MgO Oxygen is called the oxidizing agent, and magnesium is the substance oxidized. Reduction:

More information

Oxidation-Reduction Reactions

Oxidation-Reduction Reactions Chapter 18 Oxidation-Reduction Reactions Note to teacher: You will notice that there are two different formats for the Sample Problems in the student textbook. Where appropriate, the Sample Problem contains

More information

1. When the reaction Cu + HNO 3 Cu 2+ + NO + H 2 O is balanced in acidic solution, the coefficient of H + is. A) 2 B) 4 C) 3 D) 6

1. When the reaction Cu + HNO 3 Cu 2+ + NO + H 2 O is balanced in acidic solution, the coefficient of H + is. A) 2 B) 4 C) 3 D) 6 1. When the reaction Cu + HNO 3 Cu 2+ + NO + H 2 O is balanced in acidic solution, the coefficient of H + is. A) 2 B) 4 C) 3 D) 6 2. The number of moles of hydroxide ions needed to balance the disproportionation

More information

Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions.

Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. In electrochemical reactions, electrons are transferred from one species to another. Learning goals and

More information

Electrochemistry: study of the relationship between chemical change and electrical energy

Electrochemistry: study of the relationship between chemical change and electrical energy Electrochemistry Electrochemistry Chapter 20 Electrochemistry Electrochemistry: study of the relationship between chemical change and electrical energy Investigated through use of electrochemical cells:

More information

20. ELECTROCHEMISTRY. Solutions to Exercises

20. ELECTROCHEMISTRY. Solutions to Exercises 0. ELECTROCHEMISTRY Solutions to Exercises Note on significant figures: If the final answer to a solution needs to be rounded off, it is given first with one nonsignificant figure, and the last significant

More information

Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions.

Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. In electrochemical reactions, electrons are transferred from one species to another. Learning goals and

More information

Chapter 18: Electrochemistry

Chapter 18: Electrochemistry Chapter 18: Electrochemistry Key topics: Galvanic cells Nernst equation Batteries; electrolysis Balancing Redox Reactions A redox reaction involves a transfer of electrons from one species to another.

More information

Cell Potential, E cell the maximum voltage of the cell. depends upon the composition of the electrodes and the [ions] in each half-cell.

Cell Potential, E cell the maximum voltage of the cell. depends upon the composition of the electrodes and the [ions] in each half-cell. 1 Standard Electrode (Reduction) Potentials The cell voltage of an electrochemical cell can be attributed to the difference in the tendencies of the two half-cells to undergo reduction= reduction potential

More information

Electrochemistry Worksheet

Electrochemistry Worksheet Electrochemistry Worksheet 1. Assign oxidation numbers to each atom in the following: a. P 4 O 6 b. BiO 3 c. N 2 H 4 d. Mg(BrO 4 ) 2 e. MnSO 4 f. Mn(SO 4 ) 2 2. For each of the reactions below identify

More information

G = 96.5nE cell ( G in kj) log K = ne /0.0592

G = 96.5nE cell ( G in kj) log K = ne /0.0592 1 General Chemistry II Jasperse Electrochemistry. Extra Practice Problems Oxidation Numbers p1 Free Energy and Equilibrium p10 Balancing Redox; Electrons Transferred; Oxidizing p2 K Values and Voltage

More information

CHAPTER 17 OXIDATION-REDUCTION SOLUTIONS TO REVIEW QUESTIONS

CHAPTER 17 OXIDATION-REDUCTION SOLUTIONS TO REVIEW QUESTIONS HEINS17-256-283v3.qxd 12/27/06 2:48 PM Page 256 CHAPTER 17 OXIDATION-REDUCTION SOLUTIONS TO REVIEW QUESTIONS 1. Oxidation of a metal occurs when the metal loses electrons. The easier it is for a metal

More information

Redox: IB Review Questions

Redox: IB Review Questions Redox: IB Review Questions 1. Consider the standard electrode potentials of the following reactions: Sn 4+ (aq) + 2e Sn 2+ (aq) Fe 3+ (aq) + e Fe 2+ (aq) +0.15 V +0.77 V What is the value of the cell potential

More information

V. Electrochemistry. Oxidation Numbers oxidation number: the apparent charge of an atom in a compound/ion if all bonds are considered to be ionic.

V. Electrochemistry. Oxidation Numbers oxidation number: the apparent charge of an atom in a compound/ion if all bonds are considered to be ionic. V. Electrochemistry Oxidation Numbers oxidation number: the apparent charge of an atom in a compound/ion if all bonds are considered to be ionic. Rules for Assigning Oxidation Numbers (1) The oxidation

More information

Optional Homework 6 for practice only!!!

Optional Homework 6 for practice only!!! Name: Date: Optional Homework 6 for practice only!!! 1.) Write the oxidation number for each atom in the molecules below: a. Gallium sulfide Ga 2 S 3 Ga +3 S -2 b. Chromium (III) oxide Cr 2 O 3 Cr +3 O

More information

Electrochemistry. The Corrosion of Iron. The Corrosion of Iron. Electrochemistry IV. The Effect of Metal-Metal Contact on the Corrosion of Iron

Electrochemistry. The Corrosion of Iron. The Corrosion of Iron. Electrochemistry IV. The Effect of Metal-Metal Contact on the Corrosion of Iron Electrochemistry Electrochemistry IV Corrosion: A Case of Environmental Electrochemistry Electrolytic Cells: Nonspontaneous Reactions The Corrosion of Iron The Corrosion of Iron About 25% of the steel

More information

Similarities and Differences Galvanic and Electrolytic Cell:

Similarities and Differences Galvanic and Electrolytic Cell: Electrolytic Cells Voltaic cells are driven by a spontaneous chemical reaction that produces an electric current through an outside circuit. These cells are important because they are the basis for the

More information

REVIEW QUESTIONS Chapter 18

REVIEW QUESTIONS Chapter 18 Chemistry 10 ANSWER KEY REVIEW QUESTIONS Chapter 18 1. For each of the following unbalanced equations, (i) write the half-reactions for oxidation and reduction, and (ii) balance the overall equation in

More information

Redox (Oxidation & Reduction) and Electrochemistry Chapter Assignment & Problem Set

Redox (Oxidation & Reduction) and Electrochemistry Chapter Assignment & Problem Set Redox (Oxidation & Reduction) and Electrochemistry Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Redox (Oxidation & Reduction) and Electrochemistry

More information

Chapter 14 Oxidation-Reduction Reactions

Chapter 14 Oxidation-Reduction Reactions Chapter 14 Oxidation-Reduction Reactions 14.1 (a) electrolytic cell; (b) cathode; (c) oxidation; (d) half-reaction; (e) electrochemistry; (f) electrode; (g) oxidizing agent; (h) oxidation-reduction reaction;

More information

Chapter 20 Electrochemistry

Chapter 20 Electrochemistry Chapter 20 Electrochemistry Electrochemistry deals with the relationships between electricity and chemical reactions. Oxidation-reduction (redox) reactions were introduced in Chapter 4 Can be simple displacement

More information

Write half reactions for each of the following atoms or ions. Label each as oxidation or reduction.

Write half reactions for each of the following atoms or ions. Label each as oxidation or reduction. Define each 1. Oxidation loss of electrons 2. Reduction gain of electrons 3. Oxidizing agent causes oxidation by undergoing reduction 4. Reducing agent causes reduction by undergoing oxidation Write half

More information

Homework Problem Chapter 19 Answers. Bi 3+

Homework Problem Chapter 19 Answers. Bi 3+ 19.24 Homework Problem Chapter 19 Answers a. The reactions and cell potential are Ni(s) Ni 2+ (aq) + 2e E = 0.23 V 2Cu(aq) + 2e 2Cu(s) E = 0.52 V Ni(s) + 2Cu + (aq) Ni 2+ (aq) + 2Cu(s) E cell = 0.75 V

More information

e (reduction)

e (reduction) OXIDATION-REDUCTION REACTIONS Some of the most important reaction in chemistry are oxidation-reduction (redox) reactions. In these reactions, electrons transfer from one reactant to the other. The rusting

More information

1. Given the reaction for the corrosion of aluminum: 4 Al + 3 O 2 2 Al 2 O 3

1. Given the reaction for the corrosion of aluminum: 4 Al + 3 O 2 2 Al 2 O 3 1. Given the reaction for the corrosion of aluminum: 4 Al + 3 O 2 2 Al 2 O 3 Which half-reaction correctly represents the oxidation that occurs? 1) Al + 3e Al 3+ 2) Al Al 3+ + 3e 3) O 2 + 4e 2 O 2 4) O

More information

Standand Potentials at 25 C. F 2 (g) + 2 e 2 F (aq) Ag + (aq) + e Ag(s)

Standand Potentials at 25 C. F 2 (g) + 2 e 2 F (aq) Ag + (aq) + e Ag(s) version: master Exam 4 - master This MC portion of the exam should have 18 questions. Each question is 4 points for a total of 72 points on this portion of the exam. Bubble in your answer choices on the

More information

Unit 5: Electrochemistry Theory of Redox Reactions. (26% of Chemistry 30)

Unit 5: Electrochemistry Theory of Redox Reactions. (26% of Chemistry 30) Unit 5: Electrochemistry Theory of Redox Reactions. (26% of Chemistry 30) Key Concepts: oxidation reduction oxidizing agent reducing agent oxidationreduction (redox) reaction oxidation number halfreaction

More information

20Electrochemistry. Unit Outline

20Electrochemistry. Unit Outline 20Electrochemistry Unit Outline 20.1 Oxidation Reduction Reactions and Electrochemical Cells 20.2 Cell Potentials, Free Energy, and Equilibria 20.3 Electrolysis 20.4 Applications of Electrochemistry: Batteries

More information

Oxidation and Reduction Questions

Oxidation and Reduction Questions Oxidation and Reduction Questions 1 2CO + O 2 = 2CO 2 In the above reaction the oxidation number of carbon changes from (1) +2 to +1 (2) +2 to +4 (3) +4 to +1 (4) +4 to +2 2 Which metal will react spontaneously

More information

Two Types of Chemical Rxns. Oxidation/Reduction. Two Types of Chemical Rxns. Two Types of Chemical Rxns. Review of Oxidation Numbers

Two Types of Chemical Rxns. Oxidation/Reduction. Two Types of Chemical Rxns. Two Types of Chemical Rxns. Review of Oxidation Numbers Two Types of Chemical Rxns Oxidation/Reduction Chapter 20 1. Exchange of Ions no change in charge/oxidation numbers Acid/Base Rxns NaOH + HCl Two Types of Chemical Rxns Precipitation Rxns Pb(NO 3 ) 2 (aq)

More information

Chapter 20. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Chapter 20. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Chapter 20 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The gain of electrons by an element is called. A) oxidation B) reduction C) sublimation

More information

Name (Print) Section # or TA. 1. You may use a crib sheet which you prepared in your own handwriting. This may be

Name (Print) Section # or TA. 1. You may use a crib sheet which you prepared in your own handwriting. This may be Name (Print) Section # or TA 1. You may use a crib sheet which you prepared in your own handwriting. This may be one 8-1/2 by 11 inch sheet of paper with handwriting only on one side. 2. You may use a

More information

Chemistry 40S Exam Review

Chemistry 40S Exam Review Sample Extended Answer Questions I: Aqueous Solutions Chemistry 40S Exam Review 1. Consider the reaction that takes place between 0.10 mol/l aqueous solutions of iron (III) chloride, FeCl 3, and sodium

More information

20.1 Oxidation States and Oxidation- Reduction Reactions

20.1 Oxidation States and Oxidation- Reduction Reactions Lecture Presentation Chapter 20 Yonsei University 1 20.1 Oxidation States and Oxidation- Reduction Reactions is the branch of chemistry that deals with relationships between electricity and chemical reactions

More information

Oxidation Reduction Reactions. Oxidation Loss of electrons. Reduction Gain of electrons

Oxidation Reduction Reactions. Oxidation Loss of electrons. Reduction Gain of electrons Oxidation Reduction Reactions Oxidation Loss of electrons Reduction Gain of electrons + + Zn( s ) + H ( aq ) Zn ( aq ) + H ( g ) Zn is oxidized H + is reduced Zn is the reducing agent H + is the oxidizing

More information

CHM1 Review Exam 12. Topics REDOX

CHM1 Review Exam 12. Topics REDOX CHM1 Review Exam 12 Topics REDOX REDOX Reactions Oxidation Reduction Oxidizing agent Reducing agent Galvanic (Voltaic) Cells Anode Cathode Salt bridge Electrolyte Half-reactions Voltage o Positive voltages

More information

SPRING 2000 TEST 3 solutions

SPRING 2000 TEST 3 solutions 1 SPRING 000 TEST solutions 1. Which item (a, b or c) in each of the three groups below has the lowest entropy? I. (a) 10 g ice (b) 10 g water vapor (c) 10 g liquid water II. (a) 1 mole NaCl solid (b)

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Chemistry 1C-Dr. Larson Chapter 20 Review Questions MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) is reduced in the following reaction: Cr2O7

More information

Chapter 18. Electrochemistry. Hill, Petrucci, McCreary & Perry 4 th Ed.

Chapter 18. Electrochemistry. Hill, Petrucci, McCreary & Perry 4 th Ed. Chapter 18 Electrochemistry Hill, Petrucci, McCreary & Perry 4 th Ed. Oxidation Reduction Reactions Oxidation = Loss of electrons from a chemical species = Increase in Oxidation State. Na Na + 1 electron

More information

ELECTROCHEMISTRY. these are systems involving oxidation or reduction there are several types METALS IN CONTACT WITH SOLUTIONS OF THEIR IONS

ELECTROCHEMISTRY. these are systems involving oxidation or reduction there are several types METALS IN CONTACT WITH SOLUTIONS OF THEIR IONS 1 ELECTROCHEMISTRY REDOX Reduction gain of electrons Cu + 2e > Cu(s) Oxidation removal of electrons Zn(s) > Zn + 2e HALF CELLS these are systems involving oxidation or reduction there are several types

More information

OXIDATION NUMBERS (Section 4.4)

OXIDATION NUMBERS (Section 4.4) 1 OXIDATION NUMBERS (Section 4.4) Oxidation number is the charge of an atom in a molecule if all the bonding is considered ionic. Oxidation number is different from formal charge. Using oxidation numbers

More information

1. According to Reference Table J, which metal will react spontaneously with Ag + ions, but not with Zn 2+ ions? 1) Cu 3) Al 2) Au 4) Mg 2. Which will oxidize Zn(s) to Zn 2+, but will not oxidize Pb(s)

More information

). This electrolytic solution will allow ions to flow between the two beakers. This is our internal circuit.

). This electrolytic solution will allow ions to flow between the two beakers. This is our internal circuit. Electrochemistry: The study of chemical reactions that produce electricity, and chemical reactions that take place because electricity is supplied. Electrochemical reactions include: electroplating, electrolysis

More information

Oxidation - Reduction Reactions

Oxidation - Reduction Reactions Oxidation - Reduction Reactions Oxidation and Reduction I. Oxidation States A. The oxidation rules (as summarized by Mr. Allan) 1. In compounds, hydrogen has an oxidation # of +1. In compounds, oxygen

More information

ELECTROCHEMISTRY. these are systems involving oxidation or reduction there are several types METALS IN CONTACT WITH SOLUTIONS OF THEIR IONS

ELECTROCHEMISTRY. these are systems involving oxidation or reduction there are several types METALS IN CONTACT WITH SOLUTIONS OF THEIR IONS 1 ELECTROCHEMISTRY REDOX Reduction gain of electrons Cu 2+ + 2e > Cu (s) Oxidation removal of electrons Zn (s) > Zn 2+ + 2e HALF CELLS these are systems involving oxidation or reduction there are several

More information

Electrochemistry Voltaic Cells

Electrochemistry Voltaic Cells Electrochemistry Voltaic Cells Many chemical reactions can be classified as oxidation-reduction or redox reactions. In these reactions one species loses electrons or is oxidized while another species gains

More information

Chapter 18 Electrochemistry

Chapter 18 Electrochemistry Chapter 18 Electrochemistry Oxidation Reduction Reactions where electrons are transferred from one atom to another are called oxidation reduction reactions. Redox reactions for short Atoms that lose electrons

More information

CHAPTER 21 ELECTROCHEMISTRY

CHAPTER 21 ELECTROCHEMISTRY Chapter 21: Electrochemistry Page 1 CHAPTER 21 ELECTROCHEMISTRY 21-1. Consider an electrochemical cell formed from a Cu(s) electrode submerged in an aqueous Cu(NO 3 ) 2 solution and a Cd(s) electrode submerged

More information

1.8. Electro Chemistry. Practice Exam ElectroChemistry. System LENGTH: VOLUME MASS Temperature. 1 gal = 4 qt. 1 lb = 16 oz.

1.8. Electro Chemistry. Practice Exam ElectroChemistry. System LENGTH: VOLUME MASS Temperature. 1 gal = 4 qt. 1 lb = 16 oz. Electro Chemistry Practice Exam ElectroChemistry Name (last) (First) Read all questions before you start. Show all work and explain your answers to receive full credit. Report all numerical answers to

More information

MnO2 + 4 HCl MnCl2 + 2 H2O + Cl2,

MnO2 + 4 HCl MnCl2 + 2 H2O + Cl2, 1. What is the oxidation number of manganese in? A) +7 B) +2 C) +3 D) +4 2. In which substance does phosphorus have a +3 oxidation state? A) P4O10 B) PCl5 C) Ca3(PO4)2 D) KH2PO3 3. What is the oxidation

More information

7. Redox chemistry and multiple oxidation states

7. Redox chemistry and multiple oxidation states Chemistry 2810 Lecture Notes Dr. R. T. Boeré Page 106 7. Redox chemistry and multiple oxidation states So far we have only mentioned the fact that transition elements have multiple oxidation states, but

More information

21-1. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

21-1. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 21-1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 21 Electrochemistry: Chemical Change and Electrical Work 21-2 Electrochemistry: Chemical Change and

More information

Redox and Electrochemistry

Redox and Electrochemistry Name: Thursday, May 08, 2008 Redox and Electrochemistry 1. A diagram of a chemical cell and an equation are shown below. When the switch is closed, electrons will flow from 1. the Pb(s) to the Cu(s) 2+

More information

Electrochemistry. Oxidation number. Chapter 18. 2Mg 2Mg e - Oxidation half-reaction (lose e - ) Reduction half-reaction (gain e - )

Electrochemistry. Oxidation number. Chapter 18. 2Mg 2Mg e - Oxidation half-reaction (lose e - ) Reduction half-reaction (gain e - ) Electrochemistry Chapter 18 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Electrochemical processes are oxidation-reduction reactions in which: the energy

More information

Chemistry Discussion #8, Chapter 16 Student name TA name Section

Chemistry Discussion #8, Chapter 16 Student name TA name Section Chemistry 102 2016 Discussion #8, Chapter 16 Student name TA name Section Things you should know when you leave Discussion today: 1. Reduction potential E red at standard conditions 2. Cell potential E

More information

Chemistry 30 Worksheets. Electrochemistry

Chemistry 30 Worksheets. Electrochemistry Chemistry 30 Worksheets Electrochemistry Chemistry 30 Worksheets Introduction to Redox Chemistry 1. Describe the difference between an atom and an ion. 2. Write a chemical equation that shows the formation

More information

Prince George's Community College. CHM 1030 (Mr. Shah) Electrochemistry November 11, 2011

Prince George's Community College. CHM 1030 (Mr. Shah) Electrochemistry November 11, 2011 Prince George's Community College CHM 1030 (Mr. Shah) Electrochemistry November 11, 2011 Outlines: Oxidation number and oxidation, reduction (redox reactions). Balancing redox reactions. Electrochemical

More information

Electrochemistry. Chapter 20

Electrochemistry. Chapter 20 Electrochemistry Chapter 20 1 Half-reaction method remember? Example Al (s) + Cu 2+ (aq) Al 3+ (aq) + Cu (s) Oxidation: Al (s) Al 3+ (aq) + 3e - Reduction: 2e - + Cu 2+ (aq) Cu (s) Use lowest common multiple

More information

(All questions may be completed without the use of a calculator. All answers given were generated without the use of a calculator.

(All questions may be completed without the use of a calculator. All answers given were generated without the use of a calculator. ELECTROCHEMISTRY (All questions may be completed without the use of a calculator. All answers given were generated without the use of a calculator.) 1) Balance each skeleton reaction, calculate ε cell,

More information

Energy. Question 1 The reaction between solutions of hydrochloric acid and sodium hydroxide can be represented by the following equation.

Energy. Question 1 The reaction between solutions of hydrochloric acid and sodium hydroxide can be represented by the following equation. Energy Question 1 The reaction between solutions of hydrochloric acid and sodium hydroxide can be represented by the following equation. 42 HCl(aq) + NaOH(aq) =>NaCl(aq) + H 2 O(l) H = -56.0 kj mol -1

More information

Chapter 19. Electrochemistry

Chapter 19. Electrochemistry Chapter 19. Electrochemistry What we will learn: Redox reactions Galvanic cells Standard reduction potentials Thermodynamics of redox reactions Effect of concentration on cell EMF Batteries Corrosion Electrolysis

More information

Potassium ion charge would be +1, so oxidation number is +1. Chloride ion charge would be 1, so each chlorine has an ox # of -1

Potassium ion charge would be +1, so oxidation number is +1. Chloride ion charge would be 1, so each chlorine has an ox # of -1 Chapter 18-1 1. Assign oxidation numbers to each atom in: Ni Nickel ion charge would be +2, so oxidation number is +2 Chloride ion charge would be 1, so each chlorine has an ox # of -1 Mg 2 Ti 4 Magnesium

More information

Chapter 6 Oxidation-Reduction Reactions. Section 6.1 2. Which one of the statements below is true concerning an oxidation-reduction reaction?

Chapter 6 Oxidation-Reduction Reactions. Section 6.1 2. Which one of the statements below is true concerning an oxidation-reduction reaction? Chapter 6 Oxidation-Reduction Reactions 1. Oxidation is defined as a. gain of a proton b. loss of a proton c. gain of an electron! d. loss of an electron e. capture of an electron by a neutron 2. Which

More information

Balancing Oxidation-Reduction Reactions. Oxidation-Reduction Reactions

Balancing Oxidation-Reduction Reactions. Oxidation-Reduction Reactions Oxidation-Reduction Reactions Zn added to HCl yields the spontaneous reaction Zn(s) + 2H + (aq) Zn 2+ (aq) + H 2 (g) The oxidation number of Zn has increased from 0 to 2+ The oxidation number of H has

More information

4. Using the data from Handout 5, what is the standard enthalpy of formation of BaO (s)? What does this mean?

4. Using the data from Handout 5, what is the standard enthalpy of formation of BaO (s)? What does this mean? HOMEWORK 3A 1. In each of the following pairs, tell which has the higher entropy. (a) One mole of liquid water or one mole of water vapor (b) One mole of dry ice or one mole of carbon dioxide at 1 atm

More information

ELECTROCHEMICAL CELLS

ELECTROCHEMICAL CELLS 1 ELECTROCHEMICAL CELLS Allessandra Volta (1745-1827) invented the electric cell in 1800 A single cell is also called a voltaic cell, galvanic cell or electrochemical cell. Volta joined several cells together

More information

PROVINCIAL EXAMINATION MINISTRY OF EDUCATION CHEMISTRY 12 GENERAL INSTRUCTIONS

PROVINCIAL EXAMINATION MINISTRY OF EDUCATION CHEMISTRY 12 GENERAL INSTRUCTIONS INSERT STUDENT I.D. NUMBER (PEN) STICKER IN THIS SPACE JANUARY 1996 PROVINCIAL EXAMINATION MINISTRY OF EDUCATION CHEMISTRY 12 GENERAL INSTRUCTIONS 1. Insert the stickers with your Student I.D. Number (PEN)

More information

Galvanic Cells. SCH4U7 Ms. Lorenowicz. Tuesday, December 6, 2011

Galvanic Cells. SCH4U7 Ms. Lorenowicz. Tuesday, December 6, 2011 Galvanic Cells SCH4U7 Ms. Lorenowicz 1 Electrochemistry Concepts 1.Redox reactions involve the transfer of electrons from one reactant to another 2.Electric current is a flow of electrons in a circuit

More information

In an oxidation-reduction (redox) reaction, are transferred.

In an oxidation-reduction (redox) reaction, are transferred. ch18blank Page 1 Chapter 18: Electrochemistry In an oxidation-reduction (redox) reaction, are transferred. Mg + 2 AgNO 3 Mg(NO 3 ) 2 + 2 Ag Oxidation: of electrons Reduction: of electrons Oxidizing agent:

More information

Unit 2 Review Questions

Unit 2 Review Questions Unit 2 Review Questions Over 100 years ago, Gustave Eiffel designed the support structure for the Statue of Liberty. An iron framework was constructed and overlaid with copper sheets in such a way that

More information

Electrolysis - The Electrolytic Cell

Electrolysis - The Electrolytic Cell 1 Electrolysis - The Electrolytic Cell Electrolysis: The decomposition of some substance by means of an electric current. Electrolytic Cell: A cell that requires electrical energy to cause nonspontaneous

More information

Name Electrochemical Cells Practice Exam Date:

Name Electrochemical Cells Practice Exam Date: Name Electrochemical Cells Practice Exam Date: 1. Which energy change occurs in an operating voltaic cell? 1) chemical to electrical 2) electrical to chemical 3) chemical to nuclear 4) nuclear to chemical

More information

Chemistry 122 Mines, Spring 2014

Chemistry 122 Mines, Spring 2014 Chemistry 122 Mines, Spring 2014 Answer Key, Problem Set 9 1. 18.44(c) (Also indicate the sign on each electrode, and show the flow of ions in the salt bridge.); 2. 18.46 (do this for all cells in 18.44

More information

Electrochemistry. Interconversion of electrical & chemical potential energy

Electrochemistry. Interconversion of electrical & chemical potential energy Electrochemistry Interconversion of electrical & chemical potential energy 1 Electrochemistry Always involves redox reactions. 1. Energy released by spontaneous reaction is converted to electrical energy

More information

Chemistry 4th Edition McMurry/Fay

Chemistry 4th Edition McMurry/Fay 18 Ch a pt e r Electrochemistry Chemistry 4th Edition McMurry/Fay Dr. Paul Charlesworth Michigan Technological University Redox Reactions 01 Chapter 18 Slide 2 Redox Reactions 01 Redox reaction are those

More information

Page 1 of 25. Website: Mobile:

Page 1 of 25. Website:    Mobile: Question 3.1: Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn The following is the order in which the given metals displace

More information

Sample Exercise 20.1 Identifying Oxidizing and Reducing Agents

Sample Exercise 20.1 Identifying Oxidizing and Reducing Agents Sample Exercise 20.1 Identifying Oxidizing and Reducing Agents The nickel-cadmium (nicad) battery, a rechargeable dry cell used in battery-operated devices, uses the following redox reaction to generate

More information

Oxidation & Reduction

Oxidation & Reduction I. Oxidation & Reduction oxidation atoms or ions gain a higher oxidation # reduction atoms or ions drop to a lower oxidation # OIL RIG Oxidation Is Loss, Reduction Is Gain oxidation loss of electrons (increase

More information

Chapter 18 Electrochemistry

Chapter 18 Electrochemistry General Chemistry: An Integrated Approach Hill, Petrucci, 4 th Edition Chapter 18 Electrochemistry Arnold M. Guloy University of Houston 2005, Prentice Hall, Inc. Oxidation Reduction Redox involves the

More information

14. See Table 4.2 in Chapter 4 of the text for rules for assigning oxidation numbers.

14. See Table 4.2 in Chapter 4 of the text for rules for assigning oxidation numbers. CHAPTER SEVENTEEN Review of Oxidation Reduction Reactions 13. Oxidation: increase in oxidation number; loss of electrons Reduction: decrease in oxidation number; gain of electrons 14. See Table 4. in Chapter

More information

Review: Balancing Redox Reactions. Review: Balancing Redox Reactions

Review: Balancing Redox Reactions. Review: Balancing Redox Reactions Review: Balancing Redox Reactions Determine which species is oxidized and which species is reduced Oxidation corresponds to an increase in the oxidation number of an element Reduction corresponds to a

More information