60 likes | 325 Views
Titrations. Titrations are one of the most common chemical testing techniques in the laboratory. It is extremely important in the quality control of products in the food industry.
E N D
Titrations Titrations are one of the most common chemical testing techniques in the laboratory. It is extremely important in the quality control of products in the food industry.
A titration is based on the concept of acid-base neutralization. An unknown concentration of acid (or base) can be determined by reacting a specific volume of the acid (using a pipet) with a measured volume of base (using a buret) that has a known concentration. From the balanced chemical equation and mole ratios between the base (n=cv) and the acid, the unknown concentration of the acid can be determined (c=n/v). HA(aq) + BOH(aq) BA(aq) + H2O(l) acid + base salt + water
The endpoint of the neutralization reaction is denoted by a colour change in the chemical indicator used in the titration (phenolphthalein or bromothymol blue). This point in the reaction is the “estimation” that the moles of acid is equal to the moles of base, also called the neutralization or equivalence point. C1V1 = C2V2 or CaVa = CbVb for a 1:1 mole ratio
Titrations involve the accurate measurement of volumes of samples (with unknown concentration) that are being tested/titrated using pipets in erlenmeyer flasks. Volumes of the chemical (with known concentration – called the titrant) are accurately measured using a buret. See titration steps in textbook pages 400-401