Electrolysis Flashcards
What is electrolysis?
The process of using electrolysis to decompose (break down) compounds
During electrolysis, what is the solution being broken down known as?
The electrolyte
What is needed for electrolysis
a power supply, an electrolyte, electrodes
What is the positive electrode known as?
Anode
What is the negative electrode known as?
Cathode
What are cations?
positive ions
What are anions?
negative ions
How do cations move during electrolysis?
Towards the negative cathode
How do anions move during electrolysis?
Towards the positive anode
What happens to anions at the anode?
They lose electrons to become atoms
What happens to cations at the cathode?
They gain electrons to become atons
What is an aqueous solution?
A solution dissolved in water.
Which extra ions are contained in an aqueous solution?
hydrogen and hydroxide (H+ and OH-)
What is produced at the anode and cathode during the electrolysis of copper chloride solution?
Copper at the cathode and chlorine gas at the anode
What is produced at the anode and cathode during the electrolysis of sodium chloride solution?
hydrogen gas at the cathode and chlorine gas at the anode
What is produced at the anode and cathode during the electrolysis of sodium sulphate solution?
hydrogen gas at the cathode, oxygen at the anode
What is produced at the anode and cathode during the electrolysis of sulphuric acid solution?
hydrogen gas at the cathode, oxygen at the anode
What is produced at the anode and cathode during the electrolysis of molten lead bromide?
lead at the cathode, bromine at the anode
How can you predict what will be produced at the cathode during electrolysis of an aqueous solution?
If the metal in the electrolyte is below hydrogen in the reactivity series, it will be produced. Otherwise hydrogen gas is produced
How can you predict what will be produced at the anode during electrolysis of an aqueous solution?
If the electrolyte contains chloride, bromide, iodide or fluoride, the element will be produced. Otherwise oxygen gas.
What happens to the mass of the electrodes when electrolysis of copper sulphate is carried out using copper electrodes?
The anode will gain mass and the cathode will lose mass?
What happens to the mass of the electrodes when electrolysis of copper sulphate is carried out using inert electrodes?
The mass of electrodes will not change
