Two voltaic cells are to be joined so that one will run the other as an electrolytic cell. In the first cell, one half-cell has

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Two voltaic cells are to be joined so that one will run the other as an electrolytic cell. In the first cell, one half-cell has

Au foil in 1.00 M Au(NO₃)₃, and the other half-cell has a Cr bar in 1.00 M Cr(NO₃)₃. In the second cell, one half-cell has a Co bar in 1.00 M Co(NO₃)₂, and the other half-cell has a Zn bar in 1.00 M Zn(NO₃)₂.(e) If 2.00 g of metal plates out in the voltaic cell, how much metal ion plates out in the electrolytic cell?

Chemistry

1 answer:

Alik [6] · Answer 1 · 2023-10-31T16:38:43+03:00

The metal that plates out in the electrolytic cell is zinc. The mass of zinc deposited is 0.996 g.

<h3>What is an electrolytic cell?</h3>

An electrolytic cell converts electrical energy into chemical energy. Unlike galvanic cells, electrons in electrolytic cells move in the opposite direction.

Similar to a galvanic cell, an electrolytic cell has two distinct half-cells: an oxidation half-cell and a reduction half-cell.

In an electrolytic cell, the flow of electrons from the anode, where oxidation takes place, to the cathode, where reduction takes place.

It is fueled by an external source of power (such as a battery) as the reaction in electrolytic cells is not spontaneous, an external source of electrical energy is required.

The reactions for each half cell are given by

$Au^{3+}(aq) + 3e^- \rightleftharpoons Au(s)$ E° = 1.50 V

$Cr^{3+}(aq) + 3e^- \rightleftharpoons Cr(s)$ E° = –0.74 V

$Co^{2+}(aq) + 2e^- \rightleftharpoons Co(s)$ E° = –0.28 V

$Zn^{2+}(aq) + 2e^- \rightleftharpoons Zn(s)$ E° = –0.76 V

According to Faraday's law, when two or more electrolytic cells are connected in series the mass of the substance deposited is directly proportional to its equivalent mass.

Equivalent mass of Au, $E_{Au}$ = Molar mass/no. of moles of electrons transferred