Question

(1a) Explain what happens in Oxidation AND Reduction electrochemical reactions.

(1b) What happens to the ions formed in the oxidation reaction?

Answer 1

Oxidation-reduction reactions (redox reactions) are reactions in which electrons are lost by an atom or ion in one reactant and gained by an atom or ion in another reactant. Although electrons are gained and lost in these reactions, the balanced equation for a redox reaction does not show the electrons that are being transferred. In order to tell whether a redox reaction has occurred or not, we need a way to keep track of electrons. The best way to do so is by assigning oxidation numbers to the atoms or ions involved in a chemical reaction.

Now that you know how to assign oxidation numbers to the atoms or ions present in a particular substance, how do you use those oxidation numbers to determine whether a redox reaction has occurred? How do you know which element has been oxidized and which one has been reduced?

When oxidation occurs, an element loses electrons and its oxidation number increases (becomes more positive). When reduction occurs, an element gains electrons and its oxidation number decreases or is reduced (becomes more negative).

Oxidation is the loss of electrons during a reaction by a molecule, atom or ion. ... The opposite process is called reduction, which occurs when there is a gain of electrons or the oxidation state of an atom, molecule, or ion decreases.