[kclive]

0.25 M CH₃OH: find the concentrations of each ion or molecule present in the solution.

:please:

Since (in my knowledge), CH₃OH does not dissociate in solution, this must be the final solution to the problem. How do you do this?!! :swear: All help is appreciated.

-kclive

[mike]

YEs sounds right concentration of CH3OH is 0.25M.

Unless you know K or pKa and it is forming the CH3O- ion? doubt it though, strange question huh?

[Borek]

Ka of methanol is too low for CH₃OH dissociation to be of any concern here, however, don't forget about water autodissociation.

[kclive]

What do you by K, Ka, and pKa of CH₃OH? Seems like I will be learning this later this year. But can you please simply tell me how CH₃OH dissociates without using any super-advanced science terms?:aak:

But you said there is a such thing as a CH₃O^- ion. It's probably not on my humongous ion chart I have here. So that means that CH₃OH will dissociate into CH₃O^- and H⁺ ions in solution. Voila!


Thanks for all of your help.

-kclive

:cool1:

[Garneck]

pKa for methanol is somewhat close to water and is exactly 15.2.. so there will be ions in the solution through dissociation..  

[Borek]

pKa for methanol is somewhat close to water and is exactly 15.2.. so there will be ions in the solution through dissociation..  

Can you give reference? I remembered it as about 17, but I could be wrong and I can't locate it in my books at the moment (although I am almost sure it is less then 10 feets from me )

[Garneck]

15.2 is in a table I have at home

I found a table on google, and it says 15.5 in it. Click here.

[Karakth]

If they haven't yet learned about K_a etc then I don't think they'd be asked to find how methaol and water dissociate to form the three ions.

I don't suppose it's an easy calculation, although I might be wrong. My initial reserverations come from the fact that the H⁺ ion would be shared and change the K_a for both of them...Am I wrong in this?

[Borek]

I don't suppose it's an easy calculation, although I might be wrong. My initial reserverations come from the fact that the H⁺ ion would be shared and change the K_a for both of them...Am I wrong in this?

No, it is not trivial calculation. And yes, you are wrong - K_a will be not changed

However, I will be not surprised if the correct (expected) answer will be H₂O, CH₃OH and water dissociation products (H⁺ and OH^-). Water ionization is covered together with pH, so not very late in the chemistry course.