Question

why does lower E⁰ value is preferred at anode and higher at cathode?

Answer 1

E⁰ means standard reduction potential according to the convention. So higher E⁰ menas that compound has higher tendancey for reduction than the other.

• Anode is the electrode where oxidation takes place
• Cathode is the electrode where reduction takes place

For a compound to undergo reduction on reaction with another compound, it should have higher reduction tendency which means higher E⁰ value compared to the other.

• Anode - oxidation - lower reduction tendency - lower E⁰
• Cathode - reduction - higher reduction tendency - higher E⁰

^{Hope this cleared your doubt.
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