Electrolysis Flashcards
What does the “Electro” and “Lysis” mean in Electrolysis? (2 points)
- electro= using electricity
- lysis= to split or break
What is electrolysis?
Electrolysis= splitting up ionic compounds using electricity
What happens in electrolysis based on the electrons and the ions?
Taking electrons back from the negative ions and giving them back to the positive ions
Why can electrolysis not be completed with a solid version of ionic compounds?
We must melt ionic compounds or dissolve them so that the ions are free to move
What is an electrolyte?
An electrolyte is a substance that can conduct electricity when it is dissolved in water/melted, because it contains free-moving ions
When do ions become atoms?
When they gain or lose electrons at the electrodes
What is an electrolyte?
A molten compound/solution
What are the ions attracted to?
Electrodes
Why are ions attracted to the electrodes?
They have opposite charges
What happens to the ions at the electrodes?
They turn back into atoms
How is Zn 2+ formed from a Zn atom?
Zn 2+ is formed because a Zn atom LOST 2 ELECTRONS when it reacted
How can a Zn 2+ ion become a Zn atom again?
Zn 2+ ion needs to GAIN 2 ELECTRONS BACK
Write the equation of how O2- (ion) becomes an atom and write whether it’s been oxidised or reduced
2O2- —-> O2 + 4e- (Oxidised)
OR
O2- —-> O + 2e-
In the electrolysis of zinc chloride what happens at the cathode (negative electrode) (3 points)
- positive zinc ions are attracted (Zn2+)
- each zinc ion GAINS 2 electrons to become NEUTRAL ATOM (Zn2+ + 2e- —-> Zn)
- Zinc builds up around the electrodes
In the electrolysis of zinc chloride what happens at the anode? (Positive electrode) 3 points
- the negative ions are attracted (Cl-)
- each chloride ion LOSES 1 electron to become neutral ( Cl- - 1e —> Cl)
- chlorine is given off as a gas
What is the negative electrode and what is the positive electrode? (2 points)
- negative electrode= CATHODE
- positive electrode= ANODE
Which particles move in the wires of the circuit during the electrolysis of zinc chloride?
Electrons
Write the equation for Bromide ions forming Bromine
Br- —-) Br + e-
If lithium oxide was melted and a current passed through it what would the products be at the anode and cathode? (2 points)
- cathode= lithium
- anode = oxygen
If sodium iodine was melted and a current passed through it what would the products be at the anode and cathode? (2 points)
- anode= iodine
- cathode= sodium
