Chapter 17, Problem 1QAP

(a)

To determine

To explain:

The difference between oxidation and reduction electrochemical reactions:

Answer to Problem 1QAP

The difference between oxidation and reduction electrochemical reactions is explained as below:

Explanation of Solution

Electrochemical reaction is the process that involves electron transfer between two substances mostly a metal and an electrolyte. It includes oxidation and reduction reactions that occur simultaneously. Oxidation reaction involves loss of electrons by a molecule or an atom to form a cation. This causes increase in oxidation state. Reduction reaction involves gain of electrons by an atom to form an anion. This causes decrease in oxidation state. Thus, the basic difference between oxidation and reduction electrochemical reaction involve loss and gain of electrons in an atom, respectively.

(b)

To determine

To explain:

Which reaction (oxidation and reduction) occurs at anode and which at the cathode?

Answer to Problem 1QAP

The reaction (oxidation and reduction) occurs at anode and at the cathode is explained as below.

Explanation of Solution

Oxidation and reduction reactions occur at electrodes. Anode refers to negative electrode and cathode refers to positive electrode. Oxidation takes place at the anode as it involves loss of electrons. Reduction takes place at the cathode as it involves gain of electrons.