null
US
Sign In
Sign Up for Free
Sign Up
We have detected that Javascript is not enabled in your browser. The dynamic nature of our site means that Javascript must be enabled to function properly. Please read our
terms and conditions
for more information.
Next up
Copy and Edit
You need to log in to complete this action!
Register for Free
56638
Topic 3: Electrolytic Processes
Description
Chemistry Mind Map on Topic 3: Electrolytic Processes, created by Alice Clayden on 25/04/2013.
No tags specified
chemistry
chemistry
Mind Map by
Alice Clayden
, updated more than 1 year ago
More
Less
Created by
Alice Clayden
over 11 years ago
58
1
0
Resource summary
Topic 3: Electrolytic Processes
Molten/ aqueous ionic substances (e.g copper chloride(aq))- charged ions migrate to the electrode of opposite charge and solution is separated
At anode (+) - negative ions (anions) lose electrons and are oxidised, they become atoms again. e.g. chloride ions into chlorine.
At cathode (-) - positive ions (cations) gain electrons and are reduced, they become atoms again. e.g. copper ions turn to solid copper.
Half equations show what happens at the electrodes. e.g. anode- 2Cl- > Cl2 + 2e-, cathode - Cu+ + e- > Cu
Electrolysis of sodium chloride: (salt water/ brine) electrolyte is water- ions present are Na+, Cl-, H+, OH-
Sodium (Na+) and Hydrogen (H+) ions migrate towards the cathode. H gas is given off as H+ ions gain electrons (reduction). Sodium stays in solution.
Hydrogen used for making ammonia and margarine
Hydroxide (OH-) and Chloride (Cl-) ions migrate to the anode. Cl gas given off as Cl- ions lose electrons (oxidation). Hydroxide stays in solution
Chlorine used for making bleaches, disinfectants, paints and plastics
Sodium hydroxide solution is produced (NaOH)- used in making soap, paper and synthetic fibres
Sodium metal can be obtained if molten sodium chloride is electrolysed- Na at the cathode, Cl at the anode
uses of sodium- nuclear reactants as a coolant and in street lights to make them yellow
Na+ + e- > Na
Electroplating
Coating an object e.g. silver cutlery with a thin layer of metal by electrolysis
Why do this? used to make a cheaper metal object e.g. stainless steel cutlery look more attractive and shiny by coating in silver.
Jewellery is often gold plated, and tins and car wheels are plated to protect them from corrosion
the object being plated is used as the cathode and the metal being used is the anode
Positive metal migrates over and is reduced, forms a solid mteal layer on the object
the electrolyte has to contain the relevant metal ions e.g. copper sulfate to coat a nail in copper
Purification of copper
Active electrodes used- anode is impure copper, cathode is a very small strip of pure copper
positively charged copper ions (Cu2+) move from the anode to the cathode where they reduce back to copper atoms and they form solid pure copper.
impurities are not attracted to the cathode and so are left behind and fall to the bottom of the electrolyte. It is called sludge and has some uses
it may contain valuable metallic elements e.g. gold, silver, platinum
copper sulfate solution used as electrolyte
Show full summary
Hide full summary
Want to create your own
Mind Maps
for
free
with GoConqr?
Learn more
.
Similar
Using GoConqr to study science
Sarah Egan
Electrolysis
lisawinkler10
Acids and Bases
silviaod119
Elements, Compounds and Mixtures
silviaod119
Chemistry General Quiz - 2
lauren_johncock
Chemistry Quiz General -3
lauren_johncock
Chemistry Module C2: Material Choices
James McConnell
AS Chemistry - Enthalpy Changes
Sarah H-V
The Periodic Table
asramanathan
Introduction to the Atom
Derek Cumberbatch
Acids and Bases
Sarah Egan
Browse Library