Video Transcript
Which of the following is the best
description of electrolysis? (A) The use of an electric current
to produce a solid or gas from a liquid. (B) The production of an electric
current by chemical reactions in a liquid. (C) The use of an electric current
to drive the dissolution of a solid. (D) The production of an electric
current by the dissolution of a solid. (E) The use of an electric current
to drive chemical reactions in a liquid.
The word “electrolysis” is a
combination of two different Greek roots: electro-, which now refers to electrons
and electricity, and -lysis, which means to set free or to break apart. Electrolysis therefore refers to
the fact that we can use electricity to break apart substances and turn them into
pure chemical substances or other chemicals. Electrolysis is a chemical process
where electricity is passed through an electrolyte, causing it to decompose into its
constituent elements. Electrolysis is carried out by
passing an electric current from a battery or power supply through a solution
containing ions. The solution containing ions is
called an electrolyte, and it can conduct electricity.
In order to sustain an electrolytic
reaction, we must have a complete circuit. In other words, we need to be able
to continuously get power from the battery or the power supply. To do this, our solution must
contain ions and our ions must be able to move. This is why an electrolytic cell
must be filled with a liquid electrolyte. An electrolyte is a type of
substance or mixture that contains mobile ions that can conduct electricity and
therefore undergo electrolysis. If this electrolyte is a liquid,
ions can freely move versus if the electrolyte were a solid.
As the ions migrate to their
respective electrodes, oxidation and reduction reactions occur and the electrolyte
within the electrolysis cell is broken down to form new products. Given this information, which of
our answer choices provides the best description of electrolysis?
Answer choice (A) states that
electrolysis is the use of an electric current to produce a solid or gas from a
liquid. While electrolysis can be used to
produce a solid or gas from a liquid, there are many other applications of
electrolysis. Therefore, this is probably not the
best description of electrolysis. Answer (A) is incorrect.
Answer choice (B) states that
electrolysis is the production of an electric current by chemical reactions in a
liquid. The purpose of the ions within the
solution is to facilitate the electric current passing from one electrode to
another. The solution itself is not
producing the current. This answer is not correct.
Answer choice (C) states that
electrolysis is the use of electric current to drive the dissolution of a solid. This answer is also correct in that
electrolysis can be used to dissolve a solid. However, this is not the only
application for electrolysis and is therefore not the best description of the
process. Therefore, answer choice (C) is
incorrect.
Answer choice (D) states that
electrolysis is the production of an electric current by the dissolution of a
solid. Again, as the current comes from an
outside source and not an internal reaction, this definition is incorrect.
Answer choice (E) states that
electrolysis is the use of an electric current to drive chemical reactions in a
liquid. Since this definition covers a wide
range of applications, this is the most complete and best description of
electrolysis. Therefore, answer choice (E) is
correct. The use of an electric current to
drive chemical reactions in a liquid is the correct answer.
