#vinegar_analysis
#acetic_acid_analysis
#acetic_acid
Vinegar is a dilute solution of acetic acid (CH3COOH). Only the last hydrogen in this acid is acidic, and could be neutralized by a base. The concentration of acetic acid in vinegar is determined by titrating 10.0 ml sample of it to a phenolphthalein endpoint with a measured volume of a standard NaOH solution. The moles of the acid are calculated from the balanced equation:
CH3COOH + NaOH CH3COO-Na+ + H2O
At the endpoint of the titration, the number of moles of NaOH is equal to the number of moles of CH3COOH. The mass of CH3COOH titrated in the vinegar is determined by multiplying the number of moles of CH3COOH by its molar mass (60.05 g/mol). The percentage of CH3COOH in vinegar can thus be determined