Acid Base Activity

By E Saylor

Purpose: The purpose of this activity is to experimentally determine which acid is stronger, vinegar or HCl, by comparing how each reacts with NaOH (a base), NaHCO₃ (baking soda, a carbonate), and Mg (a metal).

Prior Knowledge: As you know, acids are neutralized by bases. Acids react with carbonates to produce CO₂. Finally, acids will dissolve most metals, creating hydrogen gas in the process.

Materials needed:

vinegar
0.10 M HCl
0.10 M NaOH
baking soda
magnesium
two small beakers
universal indicator
test tube
stirring rod
matches
pipettes
balance

Procedure: You must develop a procedure for each separate part of the experiment.

Part a: NaOH
You could place an equal number of drops of vinegar and HCl into two test tubes. Add a drop of universal indicator to each. Add NaOH, drop by drop, until each is neutralized. The stronger acid will require more drops of NaOH to become neutralized than does the weaker acid. Use this method, or develop your own.

Part b: NaHCO₃ (baking soda)
Develop a method, using baking soda, that will show whether vinegar or HCl is the stronger acid. You can use baking soda in the solid state, or dissolve it in water to make an aqueous solution.

Part c: Mg

Develop a method, using magnesium metal, that will show whether vinegar or HCl is the stronger acid. (You might like to use the flame test to prove to yourself that the gas formed is H₂.)

Conclusion: For each test, state your procedure and your findings.