Question

We can make a simple voltaic cell consisting of Cu and Zn electrodes dipped in an aqueous H2SO4 solution for demonstration purposes. I am curious to know whether this has a constructible cell notation or not, since I have not come across one in any book so far.

Also, the cell reaction generates H2 gas which makes me doubt that an electric double layer involving H+ ions is formed faster than that involving Cu2+ ions from a Cu electrode. It is also For the reason that , we see no detectable blue colouration around Cu when the set up - simple cell is in operation. Is that right?

Moreover, does the acidic solution have a liquid junction potential?

Answer 1

The simple voltaic cell involving Cu and Zn electrodes in aqueous H2SO4 does have a constructible cell notation and typically includes a zinc anode and a copper cathode.

Step-by-step explanation:

A simple voltaic cell can indeed have a constructible cell notation and involves the reaction of metallic zinc with cupric ion (Cu²+) to give copper metal and Zn²+ ion. The balanced chemical equation for this voltaic cell is:

Zn(s) + Cu²+ (aq) → Zn²+ (aq) + Cu(s)

In a standard setup, a zinc strip acts as the anode and is oxidized to Zn²+ ions, while Cu²+ ions at the copper cathode are reduced to metallic copper.

When Cu electrodes are dipped in aqueous H2SO4 solution, hydrogen gas may form at the cathode instead of Cu because the reduction potential of H+ is higher than that of Cu²+. Hence, there is no blue coloration around the Cu electrode due to the lack of copper plating.

A liquid junction potential does develop in the galvanic cell, usually mitigated by a salt bridge containing ions that do not interfere with the redox reaction.