Salts and electrolysis Flashcards
What’s a base?
Neutralises the H+ ions in an acid, so an alkali but only when dissolved in water with the OH- ions
Acids react with which metals
All metals above hydrogen in the reactivity series
Acid + metal =
Salt
+ hydrogen gas
Acid + base (such as metal oxide or metal hydroxide) =
Salt
+ water
How are solids removed
Filtered
Acid + Alkali =
Salt
+ water ( H+ + OH- —-> H20)
How are salts removed
Crystallisation
What is electrolysis, explain the process
The process that uses electricity to break down ionic compounds into elements
The substance that is broken down is called the electrolyte. The circuit is made up of two electrodes that attract the oppositely charged ion.
What does PANIC stand for
Positive is anode, negative is cathode
What happens at the cathode
Positive ions gain electrons to become negatively charged, this is called a reduction
What happens at the anode
Negative ions lose electrons to become positively charged. This is oxidisation.
What is a half equation?
Shows the electrons added to produce a neutral form of it
cathode - pb2+ + 2e- —-> pb
anode - 2br- —> br2 + 2e-
How to remember which way round the half equation goes?
Cath is negative and left out
Anne is positive and always right
What’s electroplating and what is it used for
Uses electrolysis to put a thin coating of metal on an object to:
- make it look nice
- protect from corrosion
- Make it harder
- reduces the cost of using all made of metal
What gas it used at the cathode and anode
Cath - Hydrogen
Anne - Chlorine
