Question

Identify the incorrect statement from the options below for the given cell:

• A. If E_ext = 1.1 V, no flow of e– or current occurs
• B. If E_ext > 1.1 V, Zn dissolves at the Zn electrode and Cu deposits at the Cu electrode
• C. If E_ext > 1.1 V, e^- flow from Cu to Zn
• D. If E_ext < 1.1 V, Zn dissolves at the anode and Cu deposits at the cathode

Answer 1

The correct option is B

If E_ext > 1.1 V, Zn dissolves at the Zn electrode and Cu deposits at the Cu electrode

Explanation for the correct option:

The correct option is (B)

$$\begin{gathered} \mathrm{If}{\mathrm{E}}_{\mathrm{ext}}>1.1\mathrm{V},\mathrm{Zn}\mathrm{dissolves}\mathrm{at}\mathrm{Zn}\mathrm{electrode}\mathrm{and}\mathrm{Cu}\mathrm{deposits}\mathrm{at}\mathrm{Cu}\mathrm{electrode}. \\ {\mathrm{E}}_{\mathrm{cell}}^{°}=0.34-(-0.76) \\ =1.10\mathrm{volt} \\ \mathrm{If}{\mathrm{E}}_{\mathrm{ext}}>1.10\mathrm{volt} \\ \mathrm{Cu}\to \mathrm{Anode} \\ \mathrm{Zn}\to \mathrm{Cathode} \\ \mathrm{If}{\mathrm{E}}_{\mathrm{ext}}=1.10\mathrm{volt} \\ \mathrm{Zn}\to \mathrm{Anode} \\ \mathrm{Cu}\to \mathrm{Cathode} \end{gathered}$$

If E_ext > 1.1 V, Zn dissolves at the Zn electrode, and Cu deposits at the Cu electrode.

If E_ext > 1.1 V, Electron will flow from Cu to Zn, zinc will be deposited on the zinc electrode and copper will dissolve from the copper electrode.

Explanation For the Wrong Option:

(a) If E_ext = 1.1 V, no flow of e^- or current occurs.

If we supply 1.1v from outside and inside also we have 1.1v, so no current will flow.

(c) If E_ext > 1.1 V, e^- flow from Cu to Zn

If Eext > 1.1 V, Electron will flow from Cu to Zn, zinc will be deposited on the zinc electrode and copper will dissolve from the copper electrode.

We know ${\mathrm{E}}_{\mathrm{cell}}$ value is 1.1v so if we put more than 1.1v then the current will flow from Cu to Zn.

(d) If E_ext < 1.1 V, Zn dissolves at the anode, and Cu deposits at the cathode.

If we put less than 1.1v then Zn will dissolve and Cu deposits.

Final Answer: Hence, option (B) is correct. If E_ext > 1.1 V, Zn dissolves at the Zn electrode, and Cu deposits at the Cu electrode.