Chapter 14 - Electrochemistry Flashcards
What does the term electrolysis mean ?
Electrolysis is the decomposition of electrolytes using electrcity.
What does the term electrolyte mean ?
An electrolyte is an ionic liquid or solution that conducts electricity and is decomposed during the process.
Whats an anode ?
the positive electrode
Whats the cathode ?
The negative electrode
Why does conduction occur in electrolytes ?
The conduction of electricity by an electrolyte occurs because the ions can move and carry charge.
Describe what happens in the process of electrolysis of lead(ii) bromide
- it splits up into lead ions and bromide ions
- the lead ions move to the cathode and for lead atoms
- the bromide ions move to the anode and form bromine ions
What do you observe at the anode and cathode during the lead (ii) bromide electrolysis ?
Cathode :
- molten grey liquid
- reduction
Anode:
- red-brown pungent gas, bubbles
- oxidation
What are the 2 half equations for the lead (ii) bromide electrolysis ?
Pb 2+ + 2e- —————> Pb
2Br- ————-> Br2 + 2e-
Describe what happens in the process of electrolysis of lithium chloride
- splits up into lithium ions and chloride ions
- lithium ions go to cathode to from lithium atoms
- chloride ions go to anode and form chlorine molecules
What do you observe at the anode and cathode during the lithium chloride electrolysis ?
Cathode :
- molten grey liquid
- reduction
Anode :
- yellow-green pungent gas, bubbles
- oxidation
What are the 2 half equations for the electrolysis of lithium chloride ?
2Cl- ———–> Cl2 + 2e-
Li+ + e- ——-> Li
What are the anode and cathode half equations for the extraction of aluminium ?
Anode :
2O2- ——-> O2 + 4e-
Cathode :
Al3+ + 3e- ———-> Al
What are the products of electrolysis of sulphuric acid ?
oxygen and hydrogen
What are the two half equations for the electrolysis for sulphuric acid ?
Anode:
4OH- —–> O2 + 2H2O + 4e-
Cathode:
2H+ + 2e- ————-> H2
What is the main ore for aluminium ?
Bauxite
