Question

Using the relative Eo values, determine which of the following reactions are electrically possible. Cu2+(aq) + Zn(s) Zn2+(aq) + Cu(s) This equation shows that Cu is . This equation shows that Zn is . Can this redox reaction take place?

Answer 1

Answer : The correct answer is : Cu²⁺ + Zn → Cu + Zn²⁺ in which Cu is reducing and Zn is oxidizing .

Possible reaction between Cu and Zn :

To check the reactivities , E⁰ ( standard reduction potential ) Values of elements are observed . The E⁰ values for :

Cu²⁺ + 2e⁻ → Cu E⁰ = 0.34 V

Zn²⁺ + 2e⁻ → Zn E⁰ = - 0.76 V

" The more the E⁰ value of , the more it will undergo reduction easily "

Since the E⁰ value of copper is higher so it will undergo reduction easily and Zn which has lesser E⁰⁰ value ., so it will tend to oxidize easily . Hence the possible reaction is :

Cu²⁺ + Zn → Cu + Zn²⁺

This equation shows that Cu is Reducing and Zn is Oxidizing .

Hence we can this reaction can off course take place .

Answer 2

Answer:- This reaction shows that Cu is reduced and Zn is oxidized and the reaction takes place spontaneously.

Explanations:- Standard reduction potential for Zn is -0.76 V and for Cu it is +0.34 V.

More negative is the standard reduction potential more easy the oxidation is. Since the standard reduction potential for Zn is more electron negative, it is oxidized and Cu is reduced. The same is happening in the given equation and so it is spontaneous.