Electrolysis Flashcards
(11 cards)
What is electrolysis
A process that uses direct electrical current to drive a chemical reaction that would otherwise not occur spontaneously
Uses of electrolysis
Extracting metals from ores
Electroplating
Purification of metals
What are electrolytes
A substance that conducts electricity through the movement of ions, but not through the movement of electrons.
What are electrodes
A rigid electric conductor that conducts electricity through nonmetallic materials
What are cations
Positive ions (go to cathode)
What are anions
Negative ions (go to anode)
How does electrolysis work
When electricity passes through the electrolyte, the ions move towards the electrodes of opposite charge.
At the cathode (–), cations gain electrons (reduction) and form neutral atoms or molecules.
At the anode (+), anions lose electrons (oxidation) and form neutral atoms or molecules.
Whats usually the equation at the anode
eg. Cl₂ + 2e⁻→ 2Cl⁻
What’s usually the equation at the cathode[-]
Na⁺ + e⁻ → Na
How to tell if the electrodes are active or inert
If the question says graphite or platinum, it’s inert
These only let current pass through; they don’t lose or gain atoms
Use these when you want only the ions in the electrolyte to react
what happens at the cathode
a reduction reaction takes place, where positively charged ions gain electrons
