How concentrated an acid is vinegar?

1
How concentrated an acid is vinegar?

• A simple titration experiment

2
The big idea

• Acids and bases neutralize each other
• A base of known concentration can be used to
  determine the concentration of an unknown acid
• At the equivalence point, the moles of acid and
  base molecules are exactly equal
• Color change is the indication of equivalence

3
The reaction

• Acids and bases neutralize each other
• A base of known concentration can be used to
  determine the concentration of an unknown acid
• At the equivalence point, the moles of acid and
  base molecules are exactly equal
• Color change is the indication of equivalence

4

• Each mole of NaOH neutralizes one mole of acetic
  acid
• For a 1M solution, each mL is 0.001 moles of NaOH

5

• When you add EXACTLY equal moles of NaOH, the
  phenopthalein will turn pink and STAY pink
• the critical ONE DROP is the one that does it

6

• Calibrate the dropper How many mL in one drop?
• Count the drops to fill a 4 mL cuvette

7

• Do the calculation

8
Results

• What was your measured concentration of acetic
  acid in the vinegar?
• How does this compare with what the bottle says?