Question

The half-cell is a chamber in the voltaic cell where one half-cell is the site of the oxidation reaction and the other half-cell is the site of the reduction reaction. type the half-cell reaction that takes place at the anode for the chromium-silver voltaic cell. indicate the physical states of atoms and ions using the abbreviation (s), (l), or (g) for solid, liquid, or gas, respectively. use (aq) for an aqueous solution. do not include phases for electrons.

Answer 1

Start by writing a simplified reaction sequence between the two elements. For this, we need some electric potential values, which you can find in a table. Adjust based on the source that you are given, because they will differ just a little.

For the reactions, using a reductions table:

Cr3+ + 3e- —> Cd0 E=-0.74
Ag+ + e- —> Ag0. E=0.8

Because Ag+ has a larger E value, the Ag+ will oxidize Cd0 in the following reaction:

3Ag+ + Cr0 —> 3Ag0 + Cd3+

(Notice that three Ag’s are used to work for the transfer of three electrons.)

At the anode, the item in solution is oxidized so that electrons are left behind. This means that the reaction occurring at the anode is the Chromium reaction, and it looks like this:

Cr0(s) —> Cr3+(aq) + 3e-