Lecture 1 (Redox) - Pharmaceutical Analytical Chemistry III - ACU

PC 215 Teams Code: 67q0715 Dr. Christine Kamal Nessim  ‫رؤية ورسالة كلية الصيدلة‬ ‫الرؤية ‪:‬‬ ‫دوليا في المجال الصيدلي‬ ‫محميا و...

PC 215 Teams Code: 67q0715 Dr. Christine Kamal Nessim  ‫رؤية ورسالة كلية الصيدلة‬ ‫الرؤية ‪:‬‬ ‫دوليا في المجال الصيدلي‬ ‫محميا والتميز ً‬ ‫ً‬ ‫الريادة‬ ‫الرسالة ‪:‬‬ ‫تمتزم كمية الصيدلة ‪ -‬جامعة األهرام الكندية بتوفير بيئةة تعميميةة معاصةرة‬ ‫وبرامج متطورة إلعداد خريج يحافظ عمى أخالقيات المهنة ولديه الجدارات‬ ‫الالزمةةة لسةةوع العمةةل‪.‬تةةدعم الكميةةة المةةةاركة المجتمعيةةة اللعالةةة والبحةةث‬ ‫العممي مرتكزة فى ذلك عمى كوادر بةرية متميزة‪.‬‬  Course Learning Outcomes Demonstrate understanding of the pharmaceutical sciences. Understand the principles of electrochemical analysis and water analysis. Understand the pharmaceutical and analytical terms, abbreviation, and symbols related to electrochemical analysis and water analysis. Implement the knowledge of fundamental sciences to handle and analyze the synthetic pharmaceutical materials. Implement different electrochemical techniques for analysis of drugs. Apply proper instrumental techniques for standardization of raw materials. Apply the principles of different tools and instrument used in electrochemical analysis and water analysis. Recognize the proper techniques for the analysis of pharmaceuticals and raw materials. Apply proper techniques for handling and disposal of synthetic materials used in pharmaceutical field. Practice teamwork skills by evaluation of other team members. Demonstrate time-management skills. Acquire critical thinking and decision making skills to solve different problems. Practice teamwork skills by working together effectively.  Outline: Redox titration - Redox principles & Electrical properties of redox systems - Nernst equation & Factors affecting oxidation potential - Detection of endpoint in redox titration -Standard Oxidants & Reductants - Applications of redox titration Potentiometry Conductometry Water Analysis 4 Lecture 1  we measure volumes (Conc.) we measure weight  Potentiometry we measure physical  Conductometry property , Oxidation: is combination with oxygen or loss of hydrogen Reduction: is combination with hydrogen or loss of oxygen But there are many reactions don’t involve oxygen and hydrogen but still redox reactions. Oxidation: reaction involves loss of electrons. Reduction: reaction involves gain of electrons. Reduction Oxidation Loss of O2 Gain of O2 Gain of H2 Loss of H2 Decrease in oxidation Increase in oxidation number number (dec. +ve charge) (inc. +ve charge) Gain of electrons Loss of electrons Is the process of Is the process of loosing one gaining one electron or more electron or more by atoms or ions by atoms or ions i.e. increase in i.e. decrease in positive charge positive charge Oxidizing agent (Oxidant): substance which has a strong tendency to oxidize other substances and itself being reduced e.g. KMnO4 , K2Cr2O7, Iodine (I2), Cerric (Ce4+), Ferric (Fe3+ ),….. Reducing agent (Reductant): substance which has a strong tendency to reduce other substances and itself being oxidized e.g. Iodide (I-), S2O32- , Ferrous (Fe2+), Cerrous (Ce3+), …. The electrons lost during oxidation are exactly the same gained during reduction. Fe2+ Ce4+  2Fe2+ + Cl2 2 Cl- + 2Fe3+ Here Fe2+ (reducing agent) is oxidized to Fe3+ by losing one e- -Since electrons are not present free in soln, therefore there must be a cpd to accept electrons and being reduced which is Cl2. Cl2 (oxidizing agent) is reduced to 2 Cl- by accepting electrons. N.B.: Fe2+ Fe3+ Fe2+ Fe3+ Fe2+ Fe3+ 1- es- are transferred from reductant to oxidant. 2- Number of es- lost by reductant or gained by oxidant must be equal. 3- e.g. Fe3+ / Fe2+ , MnO4 1- / Mn2+ , Cu2+ / Cu1+ , Ce4+ / Ce3+ Exercise: 1) Cl2° 2 Cl- + 2e- Cl2° (oxidized) + 2e- 2 Cl- (reduced) [Reduction] [True] form form half equation 2) Mg° + 2e- Mg2+ Mg° (reduced) Mg2+ (oxidized) + 2e- [Oxidation] [True] form form half equation 3) (oxidized) (reduced) form form Ionically usually adjusted by H+ & H2O in case of oxygenated oxidizing agent as KMnO4 & K2Cr2O7  Which of the following is incorrect? a. Zn° Zn2+ + 2e- [Oxidation] b. Fe3+ + 1e- Fe2+ [Oxidation] c. Cu2+ + 2e- Cu° [Reduction] d. Cl2° + 2e- 2 Cl- [Reduction] Which of the following is correct about redox reaction? a. Electrons are transferred from reductant to oxidant b. The oxidized and reduced forms of metals are called redox systems c. Number of electrons gained by oxidant or lost by reductant must be equal d. All of the above