Data Collection

When collecting data, keep everything well organized and labeled. Think about

the experiments you will be performing. What data will need to be recorded? Set

up tables for yourself to keep the data organized.

We want to be able to quantify both the value and the repeatability of your

measurements (relative average deviation). You should have at least three trials

for each of the three vinegar samples.

Additional Considerations

Think back to last week’s titrations. We said that titrations should take between

10 and 50 mL of titrant. That means if we are using 0.100 M NaOH, that we can

deliver between 0.00100 moles and 0.00500 moles of NaOH to create a quality

titration. Therefore, the moles of acid in the analyte in the Erlenmeyer flask must

be completely reacted with somewhere between 0.00100 and 0.00500 moles of

NaOH.

Commercial vinegar samples contain roughly 5% by weight of acetic acid. If we

assume the solution has a density of 1.0 g/mL, then the approximate molarity of

acetic acid in vinegar is

Think about this when determining how much acetic acid solution to use. If you

have too many moles of acid, you can either use a smaller volume of the acid or

dilute the acid in a volumetric flask and then titrate the diluted acid.

Safety Considerations

Acids and bases can be harmful to both your skin and eyes.

Wear eye protection and wash hands regularly to avoid having harmful materials

come into contact with your eyes.

If you spill acids or bases on your skin, immediately wash thoroughly with soap

and water.

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