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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Manaphylord on August 22, 2019, 09:08:28 PM

Title: Determining Kps of Barium hydroxide
Post by: Manaphylord on August 22, 2019, 09:08:28 PM
Hello community :)

I've been struggling to solve a puzzle that our chem professor has got to us, and wanted to know if any of you got an idea about how to do it. Our task is to determine the kps of Ba(OH)2.8H2O using concentrated HCl, NaOH, Borax, Potassium hydrogen phthalate and some pH indicators that we might need. Well, that's it. I'll be really glad if any of you help me, thank you :D
Title: Re: Determining Kps of Barium hydroxide
Post by: Borek on August 23, 2019, 02:41:10 AM
Have you heard about titration?
Title: Re: Determining Kps of Barium hydroxide
Post by: Manaphylord on August 23, 2019, 06:51:00 PM
I know its going to be a titration, but why do we have to standardize a basic and an acid solution ? Will we have to add excess of acid on the Ba(OH)2 solution and titrate the excess with the standidized NaOH ?
Title: Re: Determining Kps of Barium hydroxide
Post by: Borek on August 23, 2019, 07:02:36 PM
Were you told to use everything, or were you told these just are things that are available to you?
Title: Re: Determining Kps of Barium hydroxide
Post by: Manaphylord on August 23, 2019, 07:09:38 PM
The professor said that we would have these chemicals and that's it. However, it really sounded like he was assuming that we would have to use all of them when he was explaining. I can be wrong, but idk. He also said that there was a method that does not use any of the reactants, but it demanded too much time, which we will not have ( we'll have 3h and 40 minutes to do it).
Title: Re: Determining Kps of Barium hydroxide
Post by: AWK on August 24, 2019, 02:53:35 AM
The chemical laboratory also always has reusable equipment: laboratory glassware, laboratory scales, thermometers, burettes, shakers (e.g. magnetic stirrer). You won't do anything in the laboratory without them.
From your available reagents, you should perform standardization of HCl solution and in the last step determine the content of barium hydroxide in the sample of the saturated solution. Appropriate calculations must be made at each stage.
Title: Re: Determining Kps of Barium hydroxide
Post by: Manaphylord on August 24, 2019, 07:10:02 AM
Thank you so much ! Things are so much clear now. I still have a question though... We will have to filtrate the solution of Ba(OH)2 right ? How will I know if all the base have have been solubilized ? I just have to keep stirring until I think it's enough ?
Title: Re: Determining Kps of Barium hydroxide
Post by: Borek on August 24, 2019, 09:16:03 AM
Quote from: Manaphylord on August 24, 2019, 07:10:02 AM
I just have to keep stirring until I think it's enough ?

More or less. Leaving it overnight probably won't hurt.