How do ions conduct electricity in water?

In summary, salts conduct electricity when they are in aqueous solution or in fused/molten state. NaCl is dissociated in aqueous solution into Na+ and Cl- ions. Electricity is conducted by movement of ions, yes there is mass movement and loss of energy too unlike metallic conductors.
  • #1
scientifico
181
0
Hello, in water NaCl break itself into positive and negative ions but i didn't understood how exactly works the electricity conductions... the negative ions go to positive so seen that they are negative shouldn't repel the flow of electricity causing no conduction?

thanks!
 
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  • #2
I think

The negative ions go to the positive and give up electrons while at the same time the positive ions go to the negative and steal electrons. So from the point of view of the potential loop the circuit is completed.
 
  • #3
but all is done only by ions, so where are the electrons of electric flow?
 
  • #4
Any stream of charged particles means flowing current. After all

[tex]I = \frac Q t[/tex]
 
  • #5
scientifico said:
but all is done only by ions, so where are the electrons of electric flow?

The electrons flow along the conductor that is inserted into the water to get closer to the positive ions, those electrons are fed to the conductor from the negative ions at the other end of the loop or from any other source like a wall outlet.
 
  • #6
You mean like positive ions "charge" themself with the electrons of the flow ond "discharge" them at the positive point?
 
  • #7
What happens at the electrodes is separate from the current flowing in the bulk of the solution. But you are right that some kind of reaction is needed on electrodes for the charge transfer - these are always redox reactions.
 
  • #8
scientifico said:
Hello, in water NaCl break itself into positive and negative ions but i didn't understood how exactly works the electricity conductions... the negative ions go to positive so seen that they are negative shouldn't repel the flow of electricity causing no conduction?

thanks!

scientifico said:
You mean like positive ions "charge" themself with the electrons of the flow ond "discharge" them at the positive point?

I think that this thread doesn't belong here. It must be moved to chemistry section.

Anyways, coming back to the question. Hii Scientifico ! Always remember that salts conduct electricity when they are in aqueous solution or in fused/molten state. NaCl is dissociated in aqueous solution into Na+ and Cl- ions. Electricity is conducted by movement of ions , yes there is mass movement and loss of energy too unlike metallic conductors. Let us assume that cathode and anode both are made of Graphite. If we consider water as aqeous solution then H2O <---->H+ + OH-. Here Na+ and Cl- ions are attracted to respective electrodes rather than H+ and OH- because :
1. We are taking concentrated NaCl solution. Probability of NaCl ions to be attracted to electrodes is more than H2O ions.
2. After all Na+ has greater mass than Hydrogen so it repels H+ here and there. So is Cl- to OH-.
(Electrification series play negligible role)

Na+ is attracted towards cathode. It gains electrons from cathode(negative electrode) and become neutral Na and sticks to cathode. This way cathode looses electrons.
Cl- is attracted towards anode. It looses electrons to anode(positive electrode) and become neutral Cl and is released to atmosphere as Cl2. This way anode gains electrons and these electrons flow to positive terminal of battery. This is how electricity is conducted by ions.

As LostConjugate marks "So from the point of view of the potential loop the circuit is completed."
 
  • #9
In a typical ionically charged liquid, negative ions flow in one direction, positive in the other. Some may combine, some don't.

You might find reading about electron( negative charge) and hole( positive charge) migration in semiconductors interesting...

another version of the same effects is galvanic corrosion:

http://en.wikipedia.org/wiki/Galvanic_corrosion

Cathodic protection [of underwater boat metals, for example, like through hull fittings and propellers and shafts] depends on the flow of ions in salt water...without such movement of charged particles there would be virtually no protection of boat metals.
 

What are ions?

Ions are atoms or molecules that have gained or lost one or more electrons, resulting in a positive or negative charge.

How do ions conduct electricity?

Ions conduct electricity by allowing the flow of charged particles known as ions. When an electric field is applied, the ions will move towards the opposite charged electrode, creating an electric current.

Why do only certain ions conduct electricity?

Only certain ions conduct electricity because they have free electrons that can move easily, whereas others may have their electrons tightly bound and cannot move as freely.

Can ions conduct electricity in all states of matter?

Ions can conduct electricity in liquid and aqueous states, but not in solid or gaseous states. In solids, the ions are held in a fixed position and cannot move to carry an electric current. In gases, the ions are too far apart to interact and conduct electricity.

What are some real-life applications of ions conducting electricity?

Ions conducting electricity are essential for many everyday devices, such as batteries, electrolytic cells, and electrical circuits. They are also used in industrial processes, such as metal plating and wastewater treatment.

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