titration of vinegar
Objective Determine the concentration of acetic acid of vinegar, in terms of (m/m). Introduction Neutralization is a reaction of an acid with a bases to produce a salt and water. For example, the reaction of the strong acid HCl with the strong base NaOH produces the salt sodium chloride and water HCl(aq) NaOH(aq) ( NaCl(aq) H2O(l) Since the acid, base, and salt in this reaction are all strong electrolytes, the net ionic equation for this reaction is H(aq) OH-(aq) ( H2O(l) This same result occurs in the reaction of strong acid reacts with a weak base, or a weak acid reacts with a strong base. The acid and base react to form a salt and water. The neutralization reaction provides us with one method for determining the amount of either the acid or the base in a solution. The general method employed is that of titration. Titration is a procedure for determining the amount of substance A by adding a carefully measured volume of a solution with known concentration of B until the reaction between them is just complete. Titrations are not use exclusively with acids and bases but anytime you need to determine the concentration of a species in a solution. In this lab, we will titrate a vinegar solution with a solution of sodium hydroxide, NaOH. The active ingredient in vinegar is the weak acid, acetic acid. The structure is draw below, the red hydrogen is the acid hydrogen. Meaning it will be the only hydrogen involved is this acid-base reaction. The abbreviation for acetic acid is HAc. EMBED ChemWindow.Document The sodium hydroxide will neutralize the acetic acid, HAc, in the vinegar. The Ac actually represents the acetate anion, C2H3O2-. HAc(aq) NaOH(aq) ( NaAc(aq) H2O(l) Once the neutralization reaction is complete, any additional base added will produce a basic solution. The point at which all the acetic acid has reacted with the sodium hydroxide is call the equivalence point. We can determine when the titration is complete by employing an