Module 5-8 Unit 2 Flashcards
Electrochemistry
the study of converting chemical energy to electrical energy, and vice versa
Electrochemical cell
a device that generates electrical energy from chemical reactions, and vice versa
Voltaic (galvanic)
Spontaneous reactions in the cell use a chemical reaction to generate electricity
Electrolyic Cells
Nonspontaneous reactions in the cell use electricity to force a chemical reaction to take place
Half Cells
One of the two compartments in an electrochemical cell that houses a half reaction
Electrode
A solid electrical conductor in a half-cell in an electrochemical cell
Electrolyte
An aqeous electrical conductor in the half-cell of an electrochemical cell
RED CAT
FAT CAT
Cathode
- REDuction occurs at the CAThode
- CAThode gets FATter as the reaction procedes
Gains electrons, mass increases
AN OX
FAT CAT
Anode
- the ANode is the site of OXidation
- electrons travel from From Anode To CAThode
mass decreases
Salt Bridge
U shaped tube containing an aqueous electrolyte connecting both half cells, preventing build up of charge within a cell
Porus boundary
AN unglazed porcelain cup containing an electrolyte that sits in a container of another electrolyte, connecting both half cells, preventing build up of charge within a cell
Anode and Cathode in Voltaic cells
An - Negative (repelling electrons)
Cath - positive (attracting electrons)
Spontaneous
Anode and cathode in Electrolytic cells
An - Positive (Attracting electrons)
Cath - Negative (Repelling electrons)
Nonspontanous
Cell notation
Reactant|Product||Reactant|Product
Anode —-> Cathode
Dry Cell
a Voltaic Cell where the electrolyte has been thickened into a paste
Battery
Voltaic Cells connected in series
Primary battery
a disposable battery, when reactants are used up they can’t be used anymore
Secondary battery
a reachargable battery, where reactants are used up and can be recharged using electricity
Fuel Cell
A battery that can be refuelled by running reactants through the cell and products flow out through the electrolyte membrane
Corrosion
oxidation of metals exposed to the environment
a spontaneous redox reaction
Formation of Rust
4 steps
1) Anode =Iron (eaten away)
2) Cathode = impurity in the iron
3) Elecrolyte = carbonc acid (CO2 combines with rain water)
4) “Wire” = iron itself
How to protect iron from corrosion
- protective coating
- Create an alloy
- Galvanise (protective layer)
- Cathodic prevention (saccrificial anode)
Electrolysis
process in an electrolytic cell where electricity is used to drive a nonspontaneous chemical reaction
Overpotential
potential difference (voltage) beyond the calculated value for the cell potential nessesary to drive the reacton
Electrorefining
Using electrolysis to obtain high grade metals at the cathode from impure metals at the annode
