Electrolysis Processes - Topic 3 Flashcards
What is the movement of ions like in electrolysis?
- during electrolysis positively charged ions (cations) move to the negative electrode (cathode) and negatively charged ions move to the positively charged electrode (anode)
- ions are discharged at the electrodes producing elements
What is oxidation in terms of electrons?
oxidation is the loss of electrons
What is reduction in terms of electrons?
gain of electrons
Electrolytes:
ionic compounds that conduct electricity in the molten state or dissolved in water e.g. lead bromide
Non-electrolytes:
compounds that does not conduct electricity in the molten state or dissolved in water e.g. lead bromide
Why and how do electrons move through a circuit?
electrons repelled by negative terminal and attracted to the positive terminal → flow from negative to positive
Electrolysis:
a process in which electrical energy, from a direct current supply, decomposes electrolytes
Electricity:
movement/flow of electric charge/electrons
Conductors:
material that allows charge to easily move/flow through it e.g. metals like iron
Why do metals like iron and a non-metal like graphite conduct electricity?
as they both contain electrons (can carry charge) and move through materials
Insulators:
material that does allow charge to easily move/flow through it e.g. plastic
Why do non-metals like diamond and sulphur not conduct electricity?
contain no charged particles that can move through substance - charge cannot move through the substance
Important half-equation to learn:
4OH⁻ —> 2H₂O + O₂ + 4e ⁻
Why is graphite often used as an electrode?
- conducts electricity - contains free electrons
- unreactive - so won’t react with solution and form other products
Diagram of electrolysis: