Electrolysis Flashcards
What is electrolysis
When an ionic compound is melted or dissolved in water, the ions are free to move about within the liquid or solution
What is the solution called when they are able to conduct electricity
Electrolytes
What does passing an electric current through electrolytes cause
The ions to move to the electrodes, positively charged ions move to the negative
Where do the positively gather ions move to
Negative electrode (cathode) and gain electrons - reduced
Where do the negatively charged ions move to
Positive electrode (anode) and loss electrons - oxidized
What do the ions form when they lose or gain electrons
Uncharged element that is discharged from the electrolyte
Why can’t ionic solids he electrolysed
The ions are in fixed positions and can’t move
Why can molten ionic compounds be electrolyzed
The ions can move freely and conduct electricity
How is lead bromide electrolysed
Positive metal ions are reduced to the element at the cathode
Negative non metal ions are oxidized to the element at the anode
What can you do if the metal is too reactive
Can be reduced with carbon and then electrolysis
Very expensive as lots of energy is needed to melt the ore and produce the current
Example of a reactive metal being extracted
Aluminum Extracted from the ore bauxite by electrolysis,
Has a high melting point so nice with cryolite
The molten mixture contains free ions, so it will conduct electricity
The positive aluminum attracted to negative electrode where they pick up three electrons and turn into neutral
The negative O2- are attracted to the positive electrode where they each lose two, the neutral oxygen combine to form O2 molecules
What do metals form
Positive ions
What do non metals form
Negative ions
How is lead bromide electrolysed
Molten stare using inert (chemically inactive) electrodes, the metal (lead)is produced at the cathode and the non metal (bromine) produced at the anode
Why is cryolite used
To lower melting point
