Electrolysis and reactions Flashcards
What happens to the positive ions during electrolysis?
The positive ions move to the cathode and discharge
What happens to the negative ions during electrolysis?
The negative ions move to the anode and discharge
How is more substance made during electrolysis?
- A larger current flows
- Current flows for a longer time
How do you calculate the quantity of current passed during electrolysis?
Current x Time
What happens in a fuel cell?
Hydrogen reacts with oxygen to produce an electric current
What are the advantages of fuel cells?
- Less pollution
- Efficient
- Direct energy transfer
- Lightweight
What is oxidation?
The gain of oxygen
What is reduction?
The removal of oxygen
Whats the equation for rusting?
Iron + Oxygen + Water = Hydrated iron oxide
What is a redox reaction?
A reaction which involves oxidation and reduction
Why is rusting a redox reaction?
- Iron loses electrons
- Oxygen gains electrons
Whats an oxidising agent?
A chemical that removes electrons from another substance
How can you prevent rusting?
- Galvanising
- Alloying
- Tin painting
- Sacrificial protection
Whats sacrificial protection?
Coating the iron or steel with a more reactive metal which corrodes and loses electrons
What is a displacement reaction?
A reaction where a more reactive metal will displace a less reactive metal
What type of reaction is a displacement reaction?
Redox
