Answer to Question #98678 in Physical Chemistry for Abhishek

Question

Explain button cells and also give the reactions at the anode and the cathode .

Answer 1

Solution.

The button cell is a small separate battery cell in the shape of a squat cylinder. The metal forms the lower part of the body and the positive end of the cell (cathode). The insulated top cover is the negative terminal (anode). MnO2, Ag2O, CuO can act as a cathode. As the anode can act Zn, Li. For example, MnO2 - Zn, CuO - Li.

MnO2 (cathode) - Zn(anode)

Cathode reaction:

$2MnO2 + 2H3O^+ + 2e = 2MnO(OH) + 2H2O$

Anode reaction:

$Zn^0 - 2e = Zn^{2+}$

CuO(cathode) - Li(anode)

Cathode reaction:

$CuO + H2O+2e = Cu^0 + 2OH^-$

Anode reaction:

$Li^0 - e = Li^+$

Answer:

The button cell is a small separate battery cell in the shape of a squat cylinder. The metal forms the lower part of the body and the positive end of the cell (cathode). The insulated top cover is the negative terminal (anode). MnO2, Ag2O, CuO can act as a cathode. As the anode can act Zn, Li. For example, MnO2 - Zn, CuO - Li.

MnO2 (cathode) - Zn(anode)

Cathode reaction:

$2MnO2 + 2H3O^+ + 2e = 2MnO(OH) + 2H2O$

Anode reaction:

$Zn^0 - 2e = Zn^{2+}$

CuO(cathode) - Li(anode)

Cathode reaction:

$CuO + H2O+2e = Cu^0 + 2OH^-$

Anode reaction:

$Li^0 - e = Li^+$