Question

Given that Cu + 2HCI Cu2+ + 2CI- + H2(g) has an overall reduction potential of –0.34 V, what is a valid prediction about how this reaction works? The reaction is not spontaneous and will require energy to proceed. The reverse reaction would require energy input in order to occur. The half reactions would both occur spontaneously. The reaction is not spontaneous, and it is impossible to make it occur.

Answer 1

  Cu + 2HCI → Cu²⁺ + 2CI⁻ + H2(g)

has an overall reduction potential of –0.34 V      

The correct option is:

The reaction is not spontaneous and will require energy to proceed.

Since  the overall reduction potential is negative,the reaction is not spontaneous and it requires energy to proceed.

Answer 2

The reaction is

Cu(s) + 2HCI(aq)  ---> Cu⁺² + 2CI⁻ + H₂(g)

The given E⁰cell = -0.34

The overall reduction potential is negative

A reaction is said to be spontaneous it is ΔG° is negative

The relation between ΔG° and Electrode potential is

ΔG° = -nFE°cell

as given that

E°cell = -0.34 V

The overall value of ΔG° will be positive and hence reaction must be non spontaneous

so

The reaction is not spontaneous and will require energy to proceed.