Electrolsis Of Solutions Flashcards
Why are graphite electrodes used?
Because graphite is INERT and it conducts electricity (has free electrons that are able to move through graphite)
What are the two ways to get ions in an ionic compound moving?
- MELT then to make it molten (l)
- DISSOLVE them in water to make a solution (aq)
What happens when ionic compounds are dissolved in water?
Water molecules break up into HYDROGEN ions and HYDROXIDE ions ( H+ + OH- = H2O)
How many ions will be present in an ionic solution and where are they from? (3 points)
- FOUR types of ion
- TWO from the ionic compound
- TWO from the water
What are the products formed when sodium bromide is electrolysed and why? (2 points)
Hydrogen (because it’s less reactive than sodium)
Bromine (it’s in group 7)
What are the products formed when sodium sulphate is electrolysed and why? (2 points)
- hydrogen (H+) because it’s less reactive than sodium (Na+)
- oxygen because sulfur is not in group 7
What are the products formed when silver nitrate is electrolysed and why? (2 pints)
- silver (less reactive than hydrogen)
- oxygen (nitrogen is not in group 7)
After zinc chloride is electrolysed, what is the product at the ANODE and why?
Chlorine is the product at the anode because it’s a HALOGEN (group 7)
What Is the formula for a Sulfate ion?
SO4 2- (SO4 two minus)
When copper sulphate is electrolysed then what is the product at the anode and why?
Oxygen is the product at the anode because there are no HALIDE IONS
Compare the energy process in the electrolysis of a MOLTEN ionic compound to the electrolysis of an ionic SOLUTION
Electrolysis of molten ionic compounds is a MUCH HIGHER ENERGY PROCESS than the electrolysis of an ionic solution
Why is electrolysis not good to use to extract all metals?
It is ONLY useful for extracting metals that are LESS REACTIVE THAN HYDROGEN (copper, silver, gold)
