electrochemistry
- Created by: chaztil
- Created on: 02-01-20 15:45
View mindmap
- batteries and electrchemical cells
- fuel cells
- used in cars rather than an internal combustion engine -more efficient -only waste product is water so no chemical waste -dont need to be recharged
- -energy needed to get supply of oxygen and water -hydrogen highly flammable -amny more leaks if you used the current system
- conventional representation of cells
- rechargeable and non-rechargeable cells
- lithium batteries are rechargeable - lithium cobalt oxide electrode- graphite electrode- lithium salt in organic solvent = electrolyte
- cathode (negative electrode)= Li--Li+ +e-
- anode (positive electrode) = Li+ + CoO2 + e-
- nickle cadium cell is also rechargeable - Ni is a good ox agent (so gets reduced) Cd is a good reducing agent (so gets oxidized)
- Ni reduced from +3 in NiO to +2 in Ni(OH)2
- Cd oxidised from 0 to =2 in Cd(OH)2
- non rechargeable cells are used as batteries
- the zinc carbon battery - short shelf life because the zinc casing also gets oxidized by O2 so zinc chloride could leak out of the battery
- ammonium chloride reduced to ammonium hydroxide
- zinc oxidized to zinc chloride
- its a dry cell battery as the electrolyte is a paste
- the zinc carbon battery - short shelf life because the zinc casing also gets oxidized by O2 so zinc chloride could leak out of the battery
- lithium batteries are rechargeable - lithium cobalt oxide electrode- graphite electrode- lithium salt in organic solvent = electrolyte
- creating an EMF
- required practical - measuring EMF
- the standard hydrogen electrode
- standard conditions: 1 atm - 25 degrees c - 0.1 mol/dm3 conc of H+ ions
- EMF = Erhs-Elhs
- so if you put the standardized 0.00V hydrogen electrode on the left hand side the EMF will be that of the other half cell
- hydrogen and oxygen = water
- fuel cells
Comments
No comments have yet been made