[Part 3]- Required practicals 🥼🧪 Flashcards
Describe the required practical, of how to investigate what happens when aqueous solutions undergo electrolysis. ⚡️
1) pour approximately 50cm^3 of copper (II) chloride solution into a beaker.
2) place a plastic petri-dish over the beaker- the petri disk should have two holes, and insert a carbon graphite rod into each hole [electrodes]
4) as carbon graphite is unreactive, the electrodes are inert and won’t react.
5) ; the two electrode mustn’t touch each other- this would produce a short-circuit
6) attach crocodile leads to the rods, and then connect the rods to the terminals, of a low-voltage power supply.
7) then select 4V on the power supply, and switch it on.
8) look very carefully at the two electrodes- the cathode is being coated with copper.
9) overall if copper (II) solution is electrolysed, then copper will be discharged at the anode and chlorine gas discharged at the anode.
During electrolysis of copper (II) solution, what will happen to the cathode and why ? ⚡️
- the cathode is being coated with copper. This is because, if the metal is less reactive then hydrogen, then the metal will be discharged at the cathode.
- as copper is less reactive than hydrogen, copper is discharged at the cathode
During electrolysis, what will happen at the anode ? ⚡️
- ; at the anode there will be bubbles of a gas, and the smell of chlorine in the air might be noticed.
During electrolysis, what will happen at the anode and why ? ⚡️
- ; at the anode there will be bubbles of a gas, and the smell of chlorine in the air might be noticed.
- this is because, we’re electrolysing copper (II) chloride and chloride is a halide ion.
- and whenever whenever electrolysis on an aqueous solution, carrying a halide ion is carried out, the halogen will be discharged at the anode.
- Therefore, this means that chlorine gas is produced at the anode.
During electrolysis of copper (II) chloride something happens at the anode. What can be used to prove this ? ⚡️
- if we hold damp blue litmus paper near the anode, it becomes bleached- proving the gas is chlorine.
Describe the required practical, of how to investigate what happens when aqueous solutions undergo electrolysis. ⚡️
Hint: sodium chloride solution
1) pour approximately 50cm^3 of sodium chloride solution into a beaker.
2) place a plastic petri-dish over the beaker- the petri disk should have two holes, and insert a carbon graphite rod into each hole [electrodes]
4) as carbon graphite is unreactive, the electrodes are inert and won’t react.
5) ; the two electrode mustn’t touch each other- this would produce a short-circuit
6) attach crocodile leads to the rods, and then connect the rods to the terminals, of a low-voltage power supply.
7) then select 4V on the power supply, and switch it on.
8) look very carefully at the two electrodes- at the anode, bubbles of gas are being produced- this is chlorine.
9) at the cathode, there will be gas bubbles produced- this is hydrogen
How can we prove what is at the anode, during the electrolysis of sodium chloride solution ? ⚡️
- If we hold damp blue litmus paper near the anode, it becomes bleached- proving the gas is chlorine.
What will happen at the anode, when electrolysing sodium chloride solution ? ⚡️
- sodium chloride contains the chloride ion- halide.
- and whenever whenever electrolysis on an aqueous solution, carrying a halide ion is carried out, the halogen will be discharged at the anode.
- therefore bubbles of gas, will be produced at the anode.
During the electrolysis of sodium chloride solution, what will happen at the anode ? ⚡️
- at the cathode, there will be gas bubbles produced- this is hydrogen
- This is because we’re electrolysing sodium chloride solution.
- and because sodium is more reactive than hydrogen, hydrogen gas is discharged at the cathode.
How can we prove what is at the cathode, during the electrolysis of sodium chloride solution ? ⚡️
- collecting it, and then testing it with a lit splint- hydrogen gas will produce a squeaky pop.
