Hi! We show you're using Internet Explorer 6. Unfortunately, IE6 is an older browser and everything at MindBites may not work for you. We recommend upgrading (for free) to the latest version of Internet Explorer from Microsoft or Firefox from Mozilla.
Click here to read more about IE6 and why it makes sense to upgrade.

Chemistry: Demo: Ba(OH)2 - H2SO4 Titration

Preview

Like what you see? Buy now to watch it online or download.

You Might Also Like

About this Lesson

  • Type: Video Tutorial
  • Length: 3:48
  • Media: Video/mp4
  • Use: Watch Online & Download
  • Access Period: Unrestricted
  • Download: MP4 (iPod compatible)
  • Size: 41 MB
  • Posted: 07/14/2009

This lesson is part of the following series:

Chemistry: Full Course (303 lessons, $198.00)
Chemistry: Equilibrium in Aqueous Solution (21 lessons, $31.68)
Chemistry: Acid-Base Titration (6 lessons, $11.88)

This lesson was selected from a broader, comprehensive course, Chemistry, taught by Professor Harman, Professor Yee, and Professor Sammakia. This course and others are available from Thinkwell, Inc. The full course can be found at http://www.thinkwell.com/student/product/chemistry. The full course covers atoms, molecules and ions, stoichiometry, reactions in aqueous solutions, gases, thermochemistry, Modern Atomic Theory, electron configurations, periodicity, chemical bonding, molecular geometry, bonding theory, oxidation-reduction reactions, condensed phases, solution properties, kinetics, acids and bases, organic reactions, thermodynamics, nuclear chemistry, metals, nonmetals, biochemistry, organic chemistry, and more.

Dean Harman is a professor of chemistry at the University of Virginia, where he has been honored with several teaching awards. He heads Harman Research Group, which specializes in the novel organic transformations made possible by electron-rich metal centers such as Os(II), RE(I), AND W(0). He holds a Ph.D. from Stanford University.

Gordon Yee is an associate professor of chemistry at Virginia Tech in Blacksburg, VA. He received his Ph.D. from Stanford University and completed postdoctoral work at DuPont. A widely published author, Professor Yee studies molecule-based magnetism.

Tarek Sammakia is a Professor of Chemistry at the University of Colorado at Boulder where he teaches organic chemistry to undergraduate and graduate students. He received his Ph.D. from Yale University and carried out postdoctoral research at Harvard University. He has received several national awards for his work in synthetic and mechanistic organic chemistry.

About this Author

Thinkwell
Thinkwell
2174 lessons
Joined:
11/13/2008

Founded in 1997, Thinkwell has succeeded in creating "next-generation" textbooks that help students learn and teachers teach. Capitalizing on the power of new technology, Thinkwell products prepare students more effectively for their coursework than any printed textbook can. Thinkwell has assembled a group of talented industry professionals who have shaped the company into the leading provider of technology-based textbooks. For more information about Thinkwell, please visit www.thinkwell.com or visit Thinkwell's Video Lesson Store at http://thinkwell.mindbites.com/.

Thinkwell lessons feature a star-studded cast of outstanding university professors: Edward Burger (Pre-Algebra through...

More..

Recent Reviews

This lesson has not been reviewed.
Please purchase the lesson to review.
This lesson has not been reviewed.
Please purchase the lesson to review.

All of you now have probably done a titration, an acid-base concentration, or at least you've thought about it and actually worked a problem involving an acid-base titration.
In the case of an acid-base titration, for instance, if you were titrating acetic acid with a strong base, like sodium hydroxide, you add sodium hydroxide until you reach the equivalence point. And, at the equivalence point, you've added exactly the same number of moles of base as you had originally moles of acetic acid in the flask or in the beaker. Now, the end point, or the visual indicator that tells you when you've reached the equivalence point, is usually something like phenyl phthalene, which changes color from colorless to pink. And that tells you that you've reached the equivalence point of the titration.
And what we're going to look at here is the titration of barium hydroxide, which is a sparingly soluble base, using sulfuric acid as the thing we're going to titrate with, the titrant. And the reactions that are going to occur are two: one, the barium 2 plus cations are going to react with the sulfate in the sulfuric acid and form barium sulfate; and, at the same time, the hydroxide from the barium hydroxide is going to react with the protons from sulfuric acid to form water. Now, you know that the solubility product of barium sulfate is relatively small, which mean that it isn't very soluble in water. And, similarly, the autoionization of water is something that gives rise to very low concentrations of protons in hydroxide. So, in other words, as this titration proceeds, what's going to happen is the ion concentration in the beaker is going to get smaller and smaller. And what we're going to see, hopefully, is that it'll get so small that the light bulb is going to turn off.
So I'm going to fire this up. Right now, the light bulb will be lit, because there's barium ions and hydroxide ions in the solution. But, as we do the titration, the concentration of ions in the solution is going to drop down, and the light bulb turning off will signal the end point of the titration. Now, I'm not going to keep track of all the numbers in our titration, because that's not the point. The point is to show you that we can use what is essentially a conductometric technique, where we're measuring the conductivity of the solution, and that tells us that we've arrived at the end point in the titration.
So let's take a look. Well, that didn't take very much. What we did was we added sulfuric acid. We precipitated all of the barium as barium sulfate. We neutralized the base with the acid and eventually we got to a point where the light bulb turned off. Now, I'm going to continue to add some sulfuric acid. And what do you suppose is going to happen? Well, the barium sulfate is still going to stay insoluble. It's still now floating around as a precipitate inside this solution. But we're going to add - my electrodes are moving around here - we're going to add more sulfuric acid, and sulfuric acid dissociates into protons and hydrogen sulfate anions, and also sulfate anions. So, when we do that, what's going to happen is the light bulb is going to turn back on again.
So take a look at the equations that we talked about here and you'll see why the conductivity of the solution ought to go to a relatively small value when we hit the end point of the titration. And then the conductivity goes back up when we go past the end point and start adding excess sulfuric acid.
Equilibrium in Aqueous Solution
Acid-Base Titration
CIA Demonstration: Barius Hydroxide-Sulfuric Acid Titration Page [1 of 1]

Embed this video on your site

Copy and paste the following snippet: