This problem is really much simpler than the way you are thinking about it. If there were many more positive ions, then the solution would very strongly attract negative ions and vice versa. So it’s very hard for some object to stay charged up when there are any paths for positive or negative charges to enter or leave it. That’s plain old electrostatics. Magnetism plays essentially no role in this.
The electrical force is long-range, so if, for example, a Na
+ happens to stick to the more negative part of a neutral H
2O, that doesn’t get rid of the net positive charge. The whole clump still attracts negative charge.
Then there is also a name convention: A substance which disolves in water with one of the ions being H
+ is called an acid, if one ion is OH
- it’s called a base. If both ions are something else, not a constituent of water, then it’s called a salt. Perhaps when you say the list of ions adds up almost to neutrality, you mean that the net concentration of the water ions (H
+ and OH
-) is very low compared to the total ionic concentration in sea water.
Mike W.
(published on 10/22/2007)
