c=Calculate the OH- conc in a solution containing 6.2x10(-3)M Ba(OH)2 and 1.00x10(-2)M BaCl2?
I thought of using the BaCl2 conc to find the conc of Ba initially, then use that in the ice table for Ba(OH)2, and solve for OH. But i dnot think that's right.
Chemistry-Common ions - DrBob222, Sunday, November 13, 2011 at 4:36pm
I wonder if this problem expects us to use a Ksp for Ba(OH)2 or not. If not I see no reason to have included the concn of BaCl2. (And note that Ba(OH)2 is quite soluble--I've never even looked for a Ksp for it).(Another note: look in your text and see if Ksp is listed for Ba(OH)2 in Ksp tables. If so we should use it. If not, we don't use it. :-)]
Assume not a Ksp problem.
Then Ba(OH)2 --> Ba^2+ + 2OH^-
If [Ba(OH)2] = 0.0062M then OH^- is twice that.
If you think it is a Ksp problem then use the BaCl2 as a common ion and solve for OH^-. Repost if you get stuck and explain the problem.
Chemistry-Common ions - matt, Sunday, November 13, 2011 at 6:28pm
Woooo! the easy way was correct c: Thanks man. But i still kinda don't know why you just doubled it. I thought it would havesomething to do witht he ice table and such since it was in the common ion+buffer chapter :s
Care explaining or?
Chemistry-Common ions - DrBob222, Sunday, November 13, 2011 at 7:45pm
You want an ICE chart?
.........Ba(OH)2 ==> Ba^2+ + 2OH^-
But I didn't do all of that in my mind. I looked at Ba(OH)2, I see there are 2 OH^- per molecule of Ba(OH)2 and the problem tells me the [Ba(OH)2] = 0.0062M so I know OH^- is twice that.
Chemistry-Common ions - matt, Sunday, November 13, 2011 at 8:36pm
Wow im an idiot XD thanks.
And i don't want to be a nuisance, but how would i do the next question?
0.320M (NH4)2SO4 and 0.492M NH3
(Still looking for OH- conc)
Would i find the H+ concentration from the double dissociation of the NH4compound? (i know how to find the oh from there)