Acid base titration - Pharmaceutical Analytical Chemistry II PDF

Pharmaceutical Analytical chemistry ll Section 1 , 2  Analysis Qualitative Quantitative Quantitative Analysis 1-Gravimetric analysis 2-volumetric analysis 3-instrumental analysis 2 3 Formal 4  Solution which Molecule M.W conta...

Pharmaceutical Analytical chemistry ll Section 1 , 2  Analysis Qualitative Quantitative Quantitative Analysis 1-Gravimetric analysis 2-volumetric analysis 3-instrumental analysis 2 3 Formal 4  Solution which Molecule M.W contains one HCl 36.5 gram-molecular H2SO4 98 weight of the NaOH 40 substance in one Na2CO3 106 liter of solution. NaCl 58.5 9  No. of moles Molar concentration = Volume “L” Weight “gm” No. of moles = M.W Weight “gm” M= M.W * volume “L” Weight “gm” = M * M.W * volume “L” 10  Solution which Molecule M.W /E.W contains one HCl 36.5/ 36.5 gram-equivalent H2SO4 98 / 49 weight of the NaOH 40 / 40 substance in one Na2CO3 106 / 53 liter of solution. NaCl 58.5 / 58.5 11  No. of gm equivalents Normal concentration = Volume “L” Weight “gm” No. of gm equivalents = E.W Weight “gm” N= E.W * volume “L” Weight “gm” = N * E.W * volume “L” 12 Normal concentration = No. of gm equivalents Volume “L” Weight “gm” N= E.W * volume “L” Weight “gm”* n N= MW*volume“L” N=M*n 13 Volumetric Analysis 23  Titration It’s the process of bringing a measured volume of (accurately known concentration)standard solution (Titrant) into a quantitative reaction with the substance to be determined (analyte). 24  Types of titration 1. Acid-base (neutralization) titration. 2. Precipitation titration. 3. Complex formation titration. 4. Redox titration 25 NaOH + HCl NaCl + H2O 26 End or equivalence point: The point at which reaction between titrant and analyte is just completed. indicated by change in the color of indicator. At E.P. no of moles of titrant = no of moles of analyte no of moles of NaOH = no of moles of HCl M×V (NaOH) = M'×V' (HCl) M = No of moles V (L)  Is the weight of analyte that is chemically equivalent to 1 ml of the titrant No. of milliliters of titrant equivalent to 1 gm of the sample E.W(sample) × N. (titrant) Titre = 1000 29  Mass of solute (g) % conc. = × 100 Volume of solution (mL) E.P × equivalence % conc. = × 100 Volume taken (mL) E.P is the volume of titrant equivalent to the sample 30  How can we recognize that a chemical reaction is completed? 31 It is an organic compound that shows clear visual change after the reaction between titrant and analyte is just completed ( change its color at the end point). In acid-base titration: Substance which has two colors: one in acidic medium and other in alkaline medium. (pH indicator or acid-base indicator) 32