Part A Use the table of standard reduction potentials given above to calculate t

Question

Part A Use the table of standard reduction potentials given above to calculate the equilibrium constant at standard temperature (25 ?C) for the following reaction:

Fe(s)+Ni2+(aq)?Fe2+(aq)+Ni(s) Express your answer numerically. K =

Part B Calculate the standard cell potential (E?) for the reaction X(s)+Y+(aq)?X+(aq)+Y(s) if K = 4.24×10?3. Express your answer to three significant figures and include the appropriate units.

Reduction half-reaction E W) Ag (aq) +e +Ag (s) 0.80 Cu2+ (aq) +2e Cu(s) 0.34 Sn (aq) 4e -Sn(s) 0.15 2H (aq) +2e -H2 (g) Nia (aq)+ 2e Ni(s) -0.26 Fe2+ (aq) +2e Fe(s) -0.45 Zn2 (aq) +2e Zn (s) -0.76 Ala (aq) 3e -Al (s) -1.66 Mg2+ (aq) 2e -Mg(s) 2.37

Explanation / Answer

A)
Eo(Ni2+/Ni) = -0.26 V
Eo(Fe2+/Fe) = -0.45 V

here Ni2+ is getting reduced. SO it is cathode

Eo cell = Eo cathode - Eo anode
= -0.26 - (-0.45)
= 0.19 V

number of electrons being transferred, n= 2
now use:
Eo = (0.0592/n)*log K
0.19 = (0.0592/2)*log K
log K = 6.441
K = 2.76*10^6

Answer: 2.76*10^6

B)
number of electrons being transferred, n= 1
use:
Eo = (0.0592/n)*log K
Eo = 0.0592 * log (4.24*10^-3)
= - 0.140
Answer: -0.140 V

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