In dilute aqueous copper (II) bromide (CuBr2) solution, the copper (II) ions (Cu2+) and bromide ions (Br-) are present. The half-reactions occurring at the anode (oxidation) and cathode (reduction) during electrolysis of this solution can be determined based on the standard reduction potentials of the species involved.
At the anode (oxidation), bromide ions (Br-) can be oxidized to bromine gas (Br2). The half-reaction at the anode can be written as:
2Br- → Br2 + 2e-
At the cathode (reduction), copper (II) ions (Cu2+) can be reduced to copper metal (Cu). The half-reaction at the cathode can be written as:
Cu2+ + 2e- → Cu
These half-reactions indicate the species being oxidized and reduced, as well as the transfer of electrons. During electrolysis, oxidation occurs at the anode, where electrons are released, and reduction occurs at the cathode, where electrons are gained.
It's worth noting that the direction of the current flow during electrolysis determines the anode and cathode. The anode is the electrode where oxidation takes place (electrons are released), while the cathode is the electrode where reduction occurs (electrons are gained).