Demonstrations › Acids, Bases, Buffers, Titrations

Acids, Bases, Buffers, Titrations

16.1 Sodium Hydroxide and Dry Ice
	To a solution containing dilute sodium hydroxide and universal indicator, a piece of dry ice is added. The color change of the solution is observed as the solution is first neutralized then becomes acidic.

 

16.2 Simple Buffer Action
Simple buffer action is demonstrated by adding acid and base to equal volumes of water and buffer solutions at pH 4.

 

16.3 Acid Breath
	The instructor breathes into a flask containing a colored solution. After several breaths, the color of the solution will change.

 

16.4 Buffering Capacity of Alka-Seltzer™
The buffering capacity of Alka-Seltzer is examined.

 

16.5 Lewis Acid/Base reaction (Ammonia + Copper Chloride)
	Ammonia is added to a solution containing copper chloride, producing the deep blue adduct.  When acid is added, the reaction is reversed.

 

4.8 Measuring Relative Strength of Acids Using Magnesium
The reaction of magnesium metal with different acids is used to measure their relative strengths. Hydrogen gas is formed during the reaction. Stronger acids will produce a more vigorous reaction with more bubbling. The increased bubbling with acids of different concentrations also demonstrates the affect of concentration on a reaction.

 

4.9 Relative pH of Solutions with Universal Indicator (or pH meter)
	The relative pH of some foods and household chemicals is illustrated by the use of Universal indicator. A Vernier pH meter can be used for more quantitative measurements.