Analytical Chemistry (Volumetric, Electrochemical, and Chromatographic Separation Techniques) Lecture Notes PDF

Course title: Analytical chemistry (Volumetric, Electrochemical analysis - Chromatographic Separation Techniques) Code: Chm 113 Dr. Wael Mortada  Lecture Volumetric Analysis: Acid-Base Titration (Part 1) Dr. Wael Mortada Assistan...

Course title: Analytical chemistry (Volumetric, Electrochemical analysis - Chromatographic Separation Techniques) Code: Chm 113 Dr. Wael Mortada  Lecture Volumetric Analysis: Acid-Base Titration (Part 1) Dr. Wael Mortada Assistant Professor of Analytical Chemistry Contact details: Email: [email protected] Mobile: 01022772144 Dr. Wael Mortada  Volumetric analysis: types & requirements. Titration process. Standard substances. Acid-base theory. Intended How to calculate pH for acids and Learning bases. Outcomes (ILOs) Behavior of salts in aqueous solutions Buffer solutions Acid-base titration curves Indicators for acid-base titration. Applications Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada  pH of weak acids 3g of benzoic acid (molecular mass= 122g/mol) are dissolved in 100mL of pure water. calculate the pH of the resulting solution. Ka of benzoic acid is 6.31x10-5 Answer: 2.405 Dr. Wael Mortada  pH of weak bases Test your self: Find the pH of 0.1 M NH4OH (Kb = 1.8 × 10−5 mol L−1) Answer: 11.13 Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada  Lecture Volumetric Analysis: Acid-Base Titration (Part 2) Dr. Wael Mortada Assistant Professor of Analytical Chemistry Contact details: Email: [email protected] Mobile: 01022772144 Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Titration of strong acid against strong base Dr. Wael Mortada  The main differences from the titration curve of Titration of weak strong acid against strong base 1. The initial pH is higher. acid against 2. The pH at the equivalence point is greater than strong base 7.0. 3. The steep rise interval is less pronounced Dr. Wael Mortada  The main differences from the titration curve Titration of weak of strong acid against strong base base against 1. The initial pH is more than 7.00. strong acid: 2. The pH at the equivalence point is less than 7.00. Dr. Wael Mortada Examples: Determine the concentration of HCl if it takes 10 ml of 0.5 M Ca(OH)2 to titrate 50 ml of HCl. (a) 0.1 M (b) 0.2 M (c) 0.5 M (d) 1.0 M What is the concentration of the sulphuric acid (H2SO4) solution if 50 ml of 0.5 M Ba(OH)2 solution is added to 100 ml of the solution? (a) 0.25 M (b) 0.5 M (c) 25 M (d) 50 M What is the molarity of the barium hydroxide Ba(OH)2 solution if 35 ml of 0.1 M HCl is used in the titration of 25 ml of barium hydroxide solution? (a) 0.28 (b) 0.21 (c) 0.14 (d) 0.07 (Answers: b a d) Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada Dr. Wael Mortada 1. Arrhenius defined an acid as: 2. In the equation: HF + H2O H 3 O+ + F - (a) a species that can donate a proton. (a) H2O is a base and HF is its conjugate (b) a species that can accept a proton. acid. (c) a source of OH- ions in water. (b) HF is an acid and F- is its conjugate base. (d) a source of H+ ions in water. (c) HF is a base and H3O+ is its conjugate acid. (d) HF is a base and F- is its conjugate acid. 3. Which of the following titrations will 4. Which of the following is used as an have the equivalence point at a pH less indicator in the titration of a strong acid than 7? and a weak base? (a) HCl and NH3 (a) Phenolphthalein (b) CH3COOH and NH3 (b) Thymol blue (c) HCl and NaOH (c) Fluorescein (d) CH3COOH and NaOH (d) Methyl orange 5. Which of the following is a buffer 6. If 30 ml of HCl is neutralized by 15 ml of solution? 0.2 N NaOH, then the concentration of HCl (a) H2SO4 + CuSO4 is (b) HCl + KCl (a) 0.4 N (c) NaCl + NaOH (b) 0.1 N (d) CH3COONa + CH3COOH (c) 0.3 N (d) 0.15 N Dr. Wael Mortada 7. What is the pH of a solution made by dissolving 2.5 g NaOH in 400 mL water? (Molar mass of NaOH 40 g/mol) Answer (pH = 13.2) 8. Find the pH of a 15.0 mol/L solution of ammonium hydroxide (NH4OH). Kb = 1.74 x 10-5. Answer (pH 12.2) Dr. Wael Mortada Additional Sources: MCQ: https://unacademy.com/content/neet-ug/mcqs/acid-base- titration-mcq/ https://byjus.com/neet/mcq-on-hydrogen-ion-concentration-ph- scale-and-buffer-solution/ Dr. Wael Mortada