Instructables

I have a question about electrolysis...

Why doesn't it work when I put the anode and the cathode in two different container when I am separating hydrogen and oxygen from water in electrolysis...?!

ALogan972 years ago
The circuit isn't complete. Electrolysis works because the electricity flows through the water between the anode and cathode, and when they are in two unconnected bodies of water, the electricity can't flow between the negative and positive terminals, meaning the circuit is incomplete. Maybe if you twist a paper towel as Prfesser said and spray/soak the whole towel in salt water and put an end of it in both containers, or poked a hole in the container under the water level in both containers and attached them with a straw, it would work, because then the circuit could be completed.
Or you could try connecting the two bodies of water with a copper wire.
bylerfamily5 years ago
Electricity does not flow that way.It has to be connected in some way when electrolyzing stuff.
cdubnbird5 years ago
is it a salt bridge even if there is no salt? personally i think not but Prfesser is right although liquid solution is a very poor conductor it conducts electricity none-the-less whereas two separate liquids can't complete a circuit.
Prfesser5 years ago
Because you need a complete circuit. Twist a paper towel, dip it into the solution in your containers, place one end in each container. That's called a "salt bridge". See "Electrochemistry" in a general chemistry text; it will explain what happens in the cell at the molecular level, and why some sort of contact is needed between the two half-cells. Prfesser