key ideas key words
C6 Electrolysis
C6.1 - Introduction to Electrolysis
Electrolysis: to break down using electricity (an electric current is used to break down
an ionic compound, the electrolyte)
❖ the electrolyte must be molten or of a solution, as ionic compounds only conduct
in those states (not when solid)
➢ for molten compounds, the substances produced will be pure
➢ however, when the substance is in solution, water is also present and
might form ions so the products may vary
❖ electrodes are made of inert substances, so that the electrodes don’t react with the
electrolyte
❖ opposite charges attract, so:
➢ the anode (green) is the positive electrode and will attract the
negatively-charged ion (the non-metal)
➢ and cathode (red) is the negative electrode which attracts the
positively-charged ion (the metal)
❖ when the ions reach the electrodes, they lose/gain electrons to become elements
➢ negatively-charged ions lose electrons to become neutral atoms (oxidised)
➢ positively-charged ions gain electrons to become neutral atoms (reduced)
➢ gases may be released or metals may be deposited
, key ideas key words
C6.2 - Changes at the Electrodes
❖ half equations can be used to explain what happens at each electrode
➢ half-equations can be combined to create an overall equation, and when
doing so, you must make all the charges cancel out, and remove the
electrons
❖ in aqueous solutions, the products formed aren’t always predictable
C6 Electrolysis
C6.1 - Introduction to Electrolysis
Electrolysis: to break down using electricity (an electric current is used to break down
an ionic compound, the electrolyte)
❖ the electrolyte must be molten or of a solution, as ionic compounds only conduct
in those states (not when solid)
➢ for molten compounds, the substances produced will be pure
➢ however, when the substance is in solution, water is also present and
might form ions so the products may vary
❖ electrodes are made of inert substances, so that the electrodes don’t react with the
electrolyte
❖ opposite charges attract, so:
➢ the anode (green) is the positive electrode and will attract the
negatively-charged ion (the non-metal)
➢ and cathode (red) is the negative electrode which attracts the
positively-charged ion (the metal)
❖ when the ions reach the electrodes, they lose/gain electrons to become elements
➢ negatively-charged ions lose electrons to become neutral atoms (oxidised)
➢ positively-charged ions gain electrons to become neutral atoms (reduced)
➢ gases may be released or metals may be deposited
, key ideas key words
C6.2 - Changes at the Electrodes
❖ half equations can be used to explain what happens at each electrode
➢ half-equations can be combined to create an overall equation, and when
doing so, you must make all the charges cancel out, and remove the
electrons
❖ in aqueous solutions, the products formed aren’t always predictable
