CHEM 272 Lecture Notes - Lecture 2: Equivalence Point, Methyl Red, Acid Dissociation Constant
20 Jan 2015
School
Department
Course
Professor
Document Summary
Chem272 8222: the equivalence point for a strong base/strong acid titration is a ph of 7. This is when the concentration of acid = the concentration of base. The ideal indicator would be one that changes color before and after this equivalence point. When a base is being titrated with an acid, the color change will occur when the in- to hin ratio is 10:1. Once the indicator changes color, the equivalence point has been reached. The indicator"s pka is best when equal to the ph at the equivalence point. Terrapin yellow has the pka of 7. 4 which is closest to 7: the average ph found for sample 1, the most acidic, was 4. 4. This can be used to find the concentration of h+. The indicator that corresponded to that was methyl red with a pka of 5. 0.
