Electrolysis Flashcards
What does the word “electrolysis” mean?
Splitting up a compound using electricity
What do we call the substance broken down by electrolysis?
Electrolyte
What are electrodes made from?
Un-reactive substance that conducts electricity such as graphite or platinum
How do negatively charged electrons become neutral atoms in electrolysis?
They lose electrons
What will be the formed at the electrodes in the electrolysis of molten potassium?
Potassium metal at the negative electrode and chlorine gas at the positive electrode
Why do ionic compounds need to be molten or in a solution to do electrolysis?
So the ions are free to move between the electrodes
What happens at the negative electrode during electrolysis?
Positive ions gain electrons
Why do the electrodes need to be replaced in aluminium extraction?
Oxygen reacts with graphite electrode making carbon dioxide and damaging it
Why is cryolite used in aluminium extraction?
lowers the melting point of aluminium oxide
During electrolysis of aluminium oxide, what happens at the positive electrode?
Each oxide ion lose 2 electrons to become oxygen molecules
During electrolysis of brine what happens at the negative electrode?
Aluminum ion gain 3 electrons to become aluminium atoms
What are the products of the electrolysis of brine?
Chlorine gas, hydrogen gas and sodium hydroxide
During the electrolysis of brine what happens at the positive electrode?
Each chlorine ion loses an electron to become chlorine molecules
During the electrolysis of brine what happens at the negative electrode?
Each hydrogen ion gains an electron to become hydrogen molecules
What are the uses of the products of electrolysis of brine?
Chlorine gas: bleach and PVC, hydrogen gas: Food industry sodium hydroxide: soap and paper
