Electrolysis- Chemistry Paper 1 Flashcards
Which electrode are the positive ions attracted to?
the cathode
Which electrode are the negative ions attracted to?
anode
What ions does the cathode attract?
positive ons
What ions does the anode attract?
negative ions
Why can ionic solids not undergo electrolysis?
Because the ions in ionic solids are in fixed positions and so they can’t move freely and carry a charge
During electrolysis, do ions get reduced or oxidised at the anode?
Negative non-metal ions are oxidised at the anode
During electrolysis, do ions get reduced or oxidised at the cathode?
Positive metal ions are oxidised at the cathode
In what situation will hydrogen gas be given out during the electrolysis of an ionic solid?
At the cathode, if H+ ions and metal ions are present , hydrogen gas will be produced if the metal is more reactive than hydrogen.
If halide ions are present in an aqueous solution of an ionic solid, will oxygen gas be released when the solution is electrolysed?
No, the molecules of chlorine, bromine and iodine will be formed
What test could you use to determine if hydrogen gas has been produced in an electrolysis reaction?
Hydrogen will make a squeaky pop with a lighted splint
What is aluminum’s ore called?
Bauxite
Why is aluminium mixed with cryolite?
Because aluminium oxide has a very high melting point and it’s melting point is lowered when mixed with cryolite. This saves energy and money
When can a metal be extracted using electrolysis?
When the metal is too reactive to be reduced by carbon
What happens if the metal formed at the cathode is less reactive than hydrogen?
A solid layer of pure metal will be produced instead- which will coat the cathode
Why do the positive electrodes have to be replaced?
Because over time, the oxygen produced at the anode will react with the graphite in the elctrode to form carbon dioxide. This process erodes the electrodes.
