Titration of Acids and BasesCelena EcclestonCHEM-L1102-01Partner: Rylie Bolarinho
15 April 2019
IntroductionThis experiment had two different purposes for each week. For week 1, the purpose wasto determine the concentration of a sodium hydroxide solution through standardization. For week2, the purpose was to determine the concentration of an unknown weak acid and to determinepKaof the weak acid.In this experiment, the important chemical concepts utilized are standardization,equivalence point, half-equivalence point, end point, ionization constants (Ka), titration, andtitration curves. Standardization is the process of determining the exact concentration of achemical solution through analytical procedure (1). An equivalence point indicates whenstoichiometrically equivalent amounts of acid and base are present in a reaction, and a half-equivalence point is when there is a 50:50 ratio of acid and base (2). The endpoint is referred toas the point at which the reaction is complete in a titration (1). An ionization constant,specifically Ka, quantifies the degree that an acid will ionize in a solution, typically water (3).Titration is the technique of accurately determining the volume of a solution needed to react withanother reagent (2). A titration curve is a graphical representation of the pH of a solution duringthe titrationand can be used to determine the ionization constant of the weak acid used in thisexperiment (4).The hypothesis for week 1 of this experiment is that by performing standardization, wewill be able to determine the concentration of a sodium hydroxide solution. The hypothesis forweek 2 of this experiment is that by performing a titration, we will be able to determine theconcentration and Kaof an unknown weak acid.
Experimental MethodsWEEK 1Part A: Preparing the Buret for UseTo begin, the buret was cleaned with soap solution and a brush and thoroughly rinsedwith tap water. The buret was then rinsed with five 10-mL portions of distilled water. The buretwas then checked to ensure it did not leak and that the stopcock turned freely.Part B: Standardization of Sodium Hydroxide (NaOH) Solution