Electrolysis Flashcards
What is electric current ?
The flow of electrons or ions
When do ionic compounds conduct electricity?
When molten or in solution
Why do they only conduct electricity when molten or in solution?
Because when they are solid the ions aren’t free to move around. But when they are dissolved the ions are free to move in the solution and so they conduct electricity
What is electrolysis ?
The breakdown of substances using electricity
What is an electrolyte?
Is a molten substance or solution that conducts electricity and is decomposed
What is the positive electrode called?
Anode
What is the negative electrode called?
Cathode
What are positively charged ions called?
Cations
What are negatively charged ions called?
Anions
In aqueous solutions, apart from the ions in the ionic compound ,what other ions are always present?
H+ and OH-
At the cathode when is hydrogen produced?
When the metal ions are more reactive than the H+ ions
At the cathode when is hydrogen not produced ?
If the metal ions are less reactive than the H+ ions OR if the solution is molten
At the anode what is produced ?
Cl-, I-, Br- or O2 2-
How do you work out charge?
Charge (C) = current (A) x time (s) ( Q = IT )
How big is 1 faraday?
1 faraday = 96,500 coulombs
What is the chemical name of brine?
Sodium chloride solution
What are the 3 useful products of the electrolysis of brine?
Hydrogen
Chlorine
Sodium
What is chlorine used for ?
To sterilise water supplies and make bleach
What is hydrogen used for ?
Manufacture of ammonia & manufacture of margarine
What is Sodium Hydroxide used for?
Manufacture of bleach and soap
