Concentration
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Concentration
How would we be able to determine the concentration of the H and OH ions within a solution?
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Re: Concentration
It depends on what we are given. If a weak acid is involved, then we need to use the equilibrium constant (Ka) along with the given concentrations to make an ice table and calculate [H+] or [OH-], but I don't think we'll be facing these types of problems in this course. I haven't seen the practice problems yet, but I'm assuming one type of problem that could show up is when we are given the pH or pOH. These are some formulas that could be used for this type of problem:
Another problem could involve a strong acid/base. In this situation, we assume 100% of the strong acid/base dissociates into H+/OH- ions, so initial concentration of the strong acid/base will equal the concentration of the H+/OH- ions.
Another problem could involve a strong acid/base. In this situation, we assume 100% of the strong acid/base dissociates into H+/OH- ions, so initial concentration of the strong acid/base will equal the concentration of the H+/OH- ions.
Re: Concentration
I'm sure it would have to be given in the problem. But if, for example, you were given an OH- concentration of 1x10^-8 M, you could calculate that the H3O+ concentration is 1x10^-6 M, since [H3O+] x [OH-] = 1x10^-14.
You can also do this using pH values. The pOH for this solution would be 8. pH + pOH = 14 , so the pH would have to be 6. Then convert pH=6 to concentration using the inverse of the formula pH = -log[H3O+]
You can also do this using pH values. The pOH for this solution would be 8. pH + pOH = 14 , so the pH would have to be 6. Then convert pH=6 to concentration using the inverse of the formula pH = -log[H3O+]
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