[confusedstud]

Can there be more solute than solvent? Or will the amount of solvent be more than the solute (not in the supersaturated case). Because I was thinking if I have concentrated sodium chloride to be electrolysed then chlorine gas will form through the oxidation of chlorine ions. This is because chlorine ions are more numerous than the hydroxide ions. So I was thinking that the solute is more than the solvent. However, it could also be because only some of the water manages to ionize and most of the water remains as a molecule.

So does it mean if I have a concentrated halide salt,that would eventually decrease in concentration as the halide keeps getting oxidised. After a while, the hydroxide starts to from oxygen as it becomes more concentrated. Then after a long time, when only a little water is left, will chlorine gas form again or will it just be super saturated or will the halide start forming elements instead?

In a similar case if a dilute halide salt is used, hydroxide ions will keep forming oxygen gas while the halide will increase in concentration. But since the amount of H+ and OH- will remain the same at all the time so the concentration of OH- will always be higher than the Cl-, so the chlorine gas will never be formed? Since the only way chlorine can be more concentrated than OH- is at the last part where very little water is left? So won't it precipitate as a salt rather than get oxidised? But in an O level question they said the solution becomes concentrated and hence the halide ions are oxidised. So doesn't it mean that the solute can be more than the solvent molecules? Since at the "very little water part"' is when all the water molecules have finally changed into ions form?

Thanks

[confusedstud]

So if I have concentrated NaCl will there eventually be discharge of hydroxide when it becomes less concentrated. Then after that happens can the chloride be concentrated again and be discharged? Because in a question the gave a electrolyte as dilute NaCl and after awhile they tell us that it becomes concentrated so chlorine gas is formed. But won't there be less water than solute since at any time more water will ionize to have a electrically neutal solution. So I'm not very sure if the NaCl can become concentrated enough to be discharged as won't th solution be supersaturated?

Thanks

[juanrga]

Can there be more solute than solvent? Or will the amount of solvent be more than the solute (not in the supersaturated case).

What is the definition of solute?

[confusedstud]

It is the dissolved substance. So in that case how can diluted NaCl case be concentrated again? Since once the amount of OH- get oxiditsed such that the choride ions is more numerous than hydroxide ions, the solution will already be superstaurated with more solute than solvent present.

[confusedstud]

Can there be more solute than solvent? Or will the amount of solvent be more than the solute (not in the supersaturated case).

What is the definition of solute?

But the problem is face is this
Eg in dilute NaCl solution I have 5 Na+, 5 Cl-, 10 H+ and 10 OH- with 10 molecules of H2O. So since OH- is more numerous so it would preferentially get oxidised. But as 1 H+ and OH- gets discharged, 1 molecule of H2O will ionize to form 1 H+ and 1 OH- such that there is always 10 H+ and 10 OH-. So the OH- will always be more numerous than the Cl- so it will be oxidised until all the water molecules form ions such meaning there are no more discreet H2O. Hence, when Cl- actually oxidises is when there is 5 Na+, 5 Cl- and only 4H+ and 4OH-. Because theoretically now Cl- is more numerous than the OH-. But since the amount of water (albeit in ions form) is lesser than the amount of solute (NaCl). So wouldn't it be supersaturated?

My guess will be that each time less water ionize. So the number of H+ and OH- ions decrease as more of the water get electrolysed.
Eg after the first 10 H+/OH-  gets discharged. Only 9 water molecules ionize to replace it and it slowly decreases as more water gets discharged? This way it would explain how there is enough solvent but the concentration of OH- will be less than of Cl- since the solvent is H2O.

Thanks. I hope this explanation makes sense you you cos I've been thinking of this question for a while.