Electrolysis PAPER 1 Flashcards
(18 cards)
What is electrolysis?
The breakdown of substance using electricity
What is an anode?
Positive electrode
What is a cathode?
Negative electrode
What is an electrolyte?
A molten or dissolved ionic compound where ions can move freely
Where do negative ions go to?
Anode
Where do positive ions go to?
Cathode
What does inert mean?
Unreactive
Why must the electrodes be inert?
So they dont react with the electrolyte
Why do the ions move to the electrodes?
Because a current is passed through the electrolyte pulling the ions to the electrodes
What is produced at the cathode?
A pure element
Electrons are _____ at the cathode
Gained
Electrons are _____ at the anode
Lost
What is produced at the anode?
A pure element
Where are non-metals produced?
At the anode
Where are metals produced?
At the cathode
Why is hydrogen gas produced at the cathode with an aqueous solution of sodium?
Hydrogen is less reactive than sodium so will form at the cathode
Why is electrolysis only used with metals more reactive than carbon?
- metals more reactive than carbon cannot be extracted using carbon displacement
- so electrolysis must be used
Method: electrolysis?
1) add 50cm³ of CuCl solution to beaker using measuring cylinder
2) attach crocodile leads to the rods. Connect the rods to the D.C terminals of low voltage
3) add electrodes to the solution. The rods must not touch each other
4) set 4v on the power supply and switch it on
5) observe electrodes and use tweezers to hold litmus paper next to positive electrode
6) should observe bubbles and litmus paper blue to white. Copper should form at cathode
7) repeat with different solution
