Paragraph: Redox reactions play a vital role in chemistry and biology. The values of E _ rol ^ of two half cell reactions decide which way the reaction is expected to proceed. A simple example is Daniel cell in which zinc goes into solution and copper gets deposited. Given below are a set of half-cell reactions (acidic medium) along with their E ^0 values. array ll I ₂+2 e ⁻ 2 I ⁻ ; & E ^ =0.54 ~V Cl ₂+2 e ⁻ 2 Cl ⁻ ;