Procedure: We began the lab by rinsing out the burette(the large pipe/dropper thing in the picture) with a small amount of NaOH, then filling the burette up to the 0 mL line with 0.25 M NaOH with a funnel. Next, we added 7.5 mL of vinegar to an Erlenmeyer flask using a graduated cylinder. We repeated the same measure-and-add with 20 mL of distilled water, so as to end up with enough mixture to submerge the magnetic stirrer. We added 4 drops of phenolphthalein into the flask. We then placed the flask onto the hot plate and turned up the stir setting to 360 rpm, which caused the magnetic stirrer to spin and mix the solution. We added NaOH slowly into the flask from the burette by turning the valve, which allowed water to drip into the flask. When it reached about 18 mL, we slowed the NaOH down to very, very slow drops so we could decide when the faint pink color had appeared. Our first trial finished badly, but our second-- and last-- trial went very well.
Percent Ionization of Vinegar: .474%
Why is this such a low number?The number is low because vinegar is a weak acid, meaning that there aren't many hydromium atoms in the solution.
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