C2.5 Salts and electrolysis Flashcards
If a substance is a base what ending of its name would it have?
Oxide or hydroxide
e.g. Copper oxide is a base
What do all acids contain?
H+
What do all bases contain?
OH-
What do these letter mean in a equation?
- (s)
- (l)
- (g)
- (aq)
- (s) = solid
- (l) = liquid
- (g) = gas
- (aq) = aqueous (solid but now a liquid)
What does a water and a base produce?
An alkali
What does an acid and a base produce?
Salt and water
What does an acid and a carbonate produce?
Salt and water and carbon dioxide
What does a metal and an acid produce?
Salt and hydrogen
What does a metal oxide and an acid produce?
Salt and water
Describe how crystals of calcium chloride can be made from calcium carbonate and dilute hydrochloric acid {4}
1) Add an excessive amount of calcium carbonate to hydrochloric acid
2) It fizzes. wait for it to stop and then filter it into a beaker
3) Heat the substance till half of the liquid has evaporated and some crystals have started to form
4) Leave to cool and see if crystals form
Define electrolyte
Ionic liquid or solution broken down by electrolysis
What does PANIC stand for?
P- positive A- anode N- negative I- is C- cathode
What does OIL RIG stand for?
O- oxidation
I- is
L- loss
R- reduction
I- is
G- gain
What happens to the electrons at the cathode?
They are lost (oxidation)
What happens to electrons at the anode?
It gains electrons (reduction)
In a solution such as calcium fluoride what goes to the cathode and why?
Hydrogen
because it is less reactive than fluoride so it is displaces. The hydrogen is positive so it has to go to the cathode. Hydrogen comes from the water solution. Fluoride is more reactive so it reacts with the oxygen in the water
During electroplating what goes at the cathode (negative)?
The object that needs to be coated
During electroplating what goes at the anode (positive)?
The metal the object needs to be coated with
During electroplating what should the electrolyte be (solution)?
a nitrate or sulphate of the metal that is coating the object e.g. copper nitrate/ copper sulphate
Balance these half equations (number with star is small number)
1) Al3* + + e– → Al
2) Cl2*+ + e– → Cu
1) Al3*+ + 3e– → Al
2) Cu2*+ + 2e– → Cu
