[Cr2O7 2- ]+ [14H+] + [6Fe 2+] <--> [2Cr 3+] + [7 H2O] + [6Fe 3+] Please show al

Question

[Cr2O7 2- ]+ [14H+] + [6Fe 2+] <--> [2Cr 3+] + [7 H2O] + [6Fe 3+]
Please show all work. Thanks. carry out include spectator ions (such as Na an Ch,whi used here, the reactions which you are not shown in this listing and which do not affect the E values Standard (1 M) acid solution Zn2++ 2 e- Zn(s) 2H+ + 2 e- H2(g) Cu2+ + e- Cu. Cu2+ + 2 e- Cu(s) 12(aq) + 2e-21- 02(g) + 2H. + 2e-H2O2 Fe3+ + e- Fe2+ Cr20+ 14H+ + 6 e- 2Cra+ + 7H20 H202 + 2H+ + 2e-2H2O Co3+ + e- CO2+ 0.76V 0.00 V 0.15 V 0.34 V 0.54 V 0.695 V 0.77V 1.23 V 1.78 V 1.92V Neutral solution (interpolated values) Cu2+ + e- Cu+ Og(g) + 2H+ + 2e-H2O2 2CroA + 16H+ + 6 e-2Cr3+ + 8H20 Cu2+ + 2e- Cu(s) 12(aq) + 2 e-21- Fe3+ + e- Fe2+ H22 + 2H+ + 2 e-2H2O Co3+ + e- CO2+ 0.15 V 0.27 V 0.27 V 0.34 V 0.54V 0.77 V 1.36 V 1.92V Standard (1 M) base solution Fe(OH)3(s) + e--> Fe(OH)2(s) + OH. Cu(OH)2(s) + 2 e- Cu(s) + 2 OH- Og(g) + 2 H2O + 2 e-H2O2 + 2 OH- Cr042-+ 4 H2O + 3 e- Cr(OH)3(s) + 5 OH. 2 Cu(OH)(s) + 2e CuzO(s) + 2 OH + H,O Co(OH)3(s) + e- Co(OH)2(s) + OH- k(aq) + 2e-21- H2O2 + 2e-2OH -0.56 v -0.22 V -0.15V -0.13 V -0.08V 0.17 V 0.54 V 0.94 V

Explanation / Answer

Cr2O72- + 14H+ + 6 e- --------> 2Cr3+ + 7 H2O E = 1.23 V

Fe3+ +e- --------------> Fe2+ E = 0.77 V

Then,

Fe2+ ----------->  Fe3+ +e-     E = - 0.77 V

6Fe2+ -----------> 6Fe3+ + 6e-    E = - 0.77 V ---------- Eq (1)

Cr2O72- + 14H++ 6 e- --------> 2Cr3+ + 7 H2O E = 1.23 V ----------- Eq (2)

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On adding Eq(1) and Eq(2),

Cr2O72- + 14H++ 6Fe2+  --------> 2Cr3+ + 7 H2O + 6Fe3+

Then,

Erxn = -0.77 V + 1.23 V = + 0.46 V

Therefore,

E rxn = + 0.46 V

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