chapter 10 Flashcards
galvanic cells
an arrangment of two connected half cells that spontaneously produces electric current- produces current when redox reaction occurs
electrodes
a plate at which either a reduction (cathode) or oxidation (anode) reaction occurs
anode
electrode where oxidation occurs
cathode
electrode where reduction occurs
electrolytes
solution that has ions (cations) and anions a solution that conducts electricty
inert electrode
provides surface for reaction to take place but does not participate in redox reaction
components of galvanic cell
-each electrode is in contact
-electrolytes surrounding each electrode are separated by a boundary
-external wire completes circuit
-cell can be divided into two parts (half cells) and a salt bridge or in a porous cup
what happens in galvanic cell
- strongest oxidizing agent undergoes reduction at cathode
-strongest reduction agent undergoes oxidization at anode
-electrons move through wire from anode to the cathode
-ions move through porous boundary to maintain electrical balance
how to tell which is oxidizing agent
greater standard reduction potential means it is stronger oxidizing agent and is a cathode
how do electrons flow
from the anode to the cathode
standard cell potential equation
Erocell= Ercathode- Eranode
standard hydrogen half cell
the galvanic cell from which all half cell potentials are determined Ero=0V
electroylitc cell
uses current from an outside source to make an electrolytic reaction occur in a process called electrolysis
galvanic cells vs electro converting
G- chemical energy–> electrical energy
E- electrical energy–> chemical energy
what does an electrolytic cell require
- electrodes
- atleast 1 electrolyte
- an external circuit
electroplating metals
protects metals that easily corrode by applying thin coating of metal that resists corrosion
3 types of electrolyic cells
- inert eleectrodes immersed in molten ionic compound only (normal)
- inert electrodes immersed in aqueous solution, include water
- non inert electrodes are immersed in aqueous solution, include water and the solid metal is always an anode
what determines mass of a cell
the quantity of electrons that pass throuhg a cell
current
I, the flow of electrons measured in amperes (A)
charge
q, product of current, measured in coulombs (C)
electrical quantities formula
q=It
faradays constant
9.65x10^4
if ecell is positive
its spontaneous and galvanic
if ecell is negative
not spontaneous, electirolysis
