Based on the following electrochemical cell,what is the standard reduction potential of metal M at 298 K? Half-Reaction E° (V) Ni²⁺(aq)+ 2e^- →Ni(s)-0.25

Question

Quizplus · Accepted Answer

The standard reduction potential of metal M can be calculated by comparing the standard reduction potential of the following half-reaction with the one given in the question:
M(s) + 2e- → M2+(aq)
The half-reaction given in the question is:
NiS1U1P12+ + 2e- → Ni(s)
To compare the two, we need to reverse the second half-reaction and change its sign:
Ni(s) → NiS1U1P12+ + 2e-  E° = +0.25 V
Now, we can compare this with the half-reaction for M:
M(s) + 2e- → M2+(aq)  E° = ?
To make this comparison, we need to flip the sign of the standard reduction potential for M:
M2+(aq) → M(s) + 2e-  E° = -?
We can see that the half-reaction for M is identical to the given half-reaction, except that the sign of the potential is flipped. Therefore, the standard reduction potential for metal M is -(-0.25 V) = +0.25 V. 
The only choice that matches this answer is D, so D is the correct choice.

Based on the Following Electrochemical Cell,what Is the Standard Reduction