Use the References to access important values if needed for this question. A vol
ID: 881549 • Letter: U
Question
Use the References to access important values if needed for this question.
A voltaic cell is constructed from a standard Ni2+|Ni half cell (E°red = -0.250V) and a standard Cr3+|Cr half cell (E°red = -0.740V).
The anode reaction is:
The cathode reaction is:
The spontaneous cell reaction is:
The cell voltage is ___________V.
B.
Use the References to access important values if needed for this question.
A voltaic cell is constructed from a standard Co2+|Co half cell (E°red = -0.280V) and a standard Mn2+|Mn half cell (E°red = -1.180V).
The anode reaction is:
The cathode reaction is:
The spontaneous cell reaction is:
The cell voltage is ___________V.
PLEASE LABEL WHETHER EVERYTHING IS (aq) (l) (s) or (g)
Enter electrons as e-. Use smallest possible integer coefficients. If a box is not needed, leave it blank.Explanation / Answer
For a spontaneous reaction, Eocell must be +ve.
Part A.
Number of e-'s involved = 6 e-
Anode reaction : Cr(s) ------> Cr3+(aq) + 3e-
Cathode reaction : Ni2+(aq) + 2e- -----> Ni(s)
Spontaneous cell reaction : 2Cr(s) + 3Ni2+ ------> 2Cr3+(aq) + 3Ni(s)
Eocell = -0.25 + 0.74 = 0.49 V [cell voltage]
Part B.
number of e-'s involved : 2 e-
Anode reaction : Mn(s) -----> Mn2+(aq) + 2e-
Cathode reaction : Co2+(aq) + 2e- ------> Co(s)
Spontaneous cell reaction : Mn(s) + Co2+(aq) ------> Mn2+(aq) + Co(s)
Eocell = -0.280 + 1.180 = 0.90 V [cell voltage]
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