Shakhashiri has all the answers.
I like to do the demonstration of a
neutralization reaction with equal volumes of hydrochloric acid and sodium
hydroxide.
The reaction produces salt
and water.
If you mix 500 milliliters of
2-molar solutions of the acid and base, you will produce 18 mL of water (1
mole).
I learned about this demo at
ChemEd, a great conference for chemistry teachers.
In previous years, I used a 1-liter graduated
cylinder, my favorite demonstration glassware, for this reaction.
Although it always worked, the additional
volume of water was very difficult to see.
Shakhashiri has a description of this same
demo in volume 3, Demo 9.17, with the solution to my problem.
He uses volumetric flasks!
Of course!
Today, when I combined the 500 mL of acid and base, both made up in 500
mL volumetric flasks, the additional water was easily visible in the neck of a 1-liter
volumetric flask.
I added some universal
indicator to the acid and base solutions to give the demo some color.
This was an extra bonus because the two
solutions formed layers when I poured them together the 1-Liter flask.
We all enjoyed the interesting effect of the
blue and pink layers.
When I mixed the
flask, the volume increase caused pressure to build up in the flask and the
stopper popped off a couple of times.
Overall, the Demo was a great way to show the products of a
neutralization reaction, including the often-overlooked water molecules that
are formed.
Shakhashiri has all the answers. I like to do the demonstration of a
neutralization reaction with equal volumes of hydrochloric acid and sodium
hydroxide. The reaction produces salt
and water. If you mix 500 milliliters of
2-molar solutions of the acid and base, you will produce 18 mL of water (1
mole). I learned about this demo at
ChemEd, a great conference for chemistry teachers. In previous years, I used a 1-liter graduated
cylinder, my favorite demonstration glassware, for this reaction. Although it always worked, the additional
volume of water was very difficult to see. Shakhashiri has a description of this same
demo in volume 3, Demo 9.17, with the solution to my problem. He uses volumetric flasks! Of course!
Today, when I combined the 500 mL of acid and base, both made up in 500
mL volumetric flasks, the additional water was easily visible in the neck of a 1-liter
volumetric flask. I added some universal
indicator to the acid and base solutions to give the demo some color. This was an extra bonus because the two
solutions formed layers when I poured them together the 1-Liter flask. We all enjoyed the interesting effect of the
blue and pink layers. When I mixed the
flask, the volume increase caused pressure to build up in the flask and the
stopper popped off a couple of times.
Overall, the Demo was a great way to show the products of a
neutralization reaction, including the often-overlooked water molecules that
are formed.
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