Pharmaceutical Analytical Chemistry-I PharmD Clinical (PC101) 2024/2025 PDF

Pharmaceutical Analytical Chemistry-I PharmD Clinical (PC101) 2024/2025 Lecture 1 & 2 General and Physical Chemistry Dr. rer. nat. Nahla Abdelshafi  Fall 2024 Course Grading Course Timeline ❖...

Pharmaceutical Analytical Chemistry-I PharmD Clinical (PC101) 2024/2025 Lecture 1 & 2 General and Physical Chemistry Dr. rer. nat. Nahla Abdelshafi  Fall 2024 Course Grading Course Timeline ❖ Practical ------- 25 Marks ❖ General and Physical Chemistry Practical exam – 20 M Practical exam1 → week 7 (2 Lectures) Practical exam 2 → week 10 ❖ Acid base titration (aqueous + non-aqueous) Evaluation – 5M. ❖ Periodicals ------ 15 M (5 Lectures) Quizzes – 15 M (3 Quizzes) ❖ Precipitimetry (Q1→ week 4 – 4 Marks, Q2→ week 8 – 7 Marks, (3 Lectures) Q3 → week 10 – 4 Marks) ❖ Kinetics of reaction ❖ Final Exam ----- 50 M (1 Lectures) ❖ Oral Exam ----- 10 M Dr. Nahla Abdelshafi 2  Fall 2024 Course Regulations ❖ Attendance and Lecture: Lecture begins sharply on time. After 15 min, entrance is prohibited. ❖ Exceeding 25% of absence percentage, exposition to deprivation. ❖ Mobile phones should be shut down. ❖ Taking photos is completely FORBIDDEN. ❖ Audio recording of the lecture is FORBIDDEN. Dr. Nahla Abdelshafi 3  Fall 2024 Course Outline Chemistry is about molecules - their shape, structure, reactivity Molecules are everywhere - chemistry affects everything! Week Lecture Week Lecture 1 General Chemistry 7 Non-aqueous acid base 2 General Chemistry 8 Quiz 2 3 Acid base titration 1 9 Precipitimetry 1 4 Acid base titration 2 + Quiz 1 10 Precipitimetry 2 (laboratory session) 5 Acid base titration 3 11 Precipitimetry 3 + Quiz 3 6 Acid base titration 4 12 Kinetics of chemical reaction Dr. Nahla Abdelshafi 4  Fall 2024 Introduction Chemistry: is the study of matter, its properties and the changes it undergoes. Analytical Chemistry: It is often described as the area of chemistry responsible for characterizing the composition of matter, both qualitatively (what is precent) and quantitatively (how much is present). Matter: is anything that occupies space and has mass. Substance: is a form of matter that has a definite composition and distinct properties. Example: water, silver, etc… Dr. Nahla Abdelshafi 5  Fall 2024 Classification of Matter Substances: Matter that is either an element or a compound Elements and compounds can not be reduced to more basic components by physical means Elements: All units that make up all matter are called atoms If all the atoms in a sample of matter have the same identity, that kind of matter is an element The carbon in a pencil point contains only carbon atoms, carbon is an element Compounds: Compounds are material made of two or more elements combined The ratio of the different atoms is always the same for that compound Example: Water’s ratio is H2O, so in each water molecule there are two hydrogen atoms and one oxygen atom Dr. Nahla Abdelshafi 6 Fall 2024 Element or compound Dr. Nahla Abdelshafi 7  Fall 2024 Mixtures A mixture is a material that is made up of two or more substances Do not always contain the same amounts of substances that make them up A heterogeneous mixture is a mixture in which the different materials can easily be distinguished A homogenous mixture or solution is a mixture in which two or more substances are uniformly spread out and the different materials can not be easily distinguished Dr. Nahla Abdelshafi 8  Fall 2024 Matter Has mass Matter Takes up space Substance Mixture Composition definite Composition Variable Homogenous Heterogenous Evenly mixed; a Unevenly solution mixed Element Compound One kind Two or more kind of atom of atom Dr. Nahla Abdelshafi 9  Fall 2024 Physical and chemical changes Physical change: Some of the physical properties of the sample may change, but its composition remains unchanged e.g. melting of ice or sugar dissolved in water. Chemical change: One or more kinds of matter are converted to new kinds of matter with different compositions e.g. burning of paper (C, H, O).....main combustion products are CO2 & H2O as steam or digestion. Dr. Nahla Abdelshafi 10  Fall 2024 Atomic Theory of Matter We now take for granted the idea that all matter is comprised of atoms. Atom: the smallest particle that still characterizing an element and can enter into a chemical reaction. Dalton’s Atomic Theory John Dalton’s theory: An element is composed of tiny particles called atoms. Atoms of the same element show the same properties while atoms of different elements show different properties. In an ordinary chemical reaction, atoms move from one substance to another, but no atom of any element disappears or is changed into an atom of another element. Compounds are formed when atoms of two or more elements combine. The weight of a compound equals the sum of the weights of the component elements Dr. Nahla Abdelshafi 11  Fall 2024 A molecule (compound) is an aggregate of two or more atoms in a definite arrangement held together by chemical forces H2 H2O NH3 CH4 A diatomic molecule contains only two atoms H2 N2 O2 Br2 HCl CO A polyatomic molecule contains more than two atoms O3, H2O, NH3, CH4 Valence Electrons Valence electrons are the electrons in the highest (last outer energy) occupied energy level of the atom. Valence electrons are the only electrons generally involved in bond formation. Dr. Nahla Abdelshafi 12  Fall 2024 Electron Dot Diagrams Show ONLY outer level electrons Also called Lewis diagrams Begin with the element’s symbol Use the periodical table to determine the number of outer level electrons Place up to 2 dots per side for a total of up to 8 electrons Put the first 2 dots together on one side, then put single dots on the remaining sides until you have to pair them 6 Ex: 87 542 electrons 13 electron X Choose a clockwise or counterclockwise direction and fill empty sides with an electron before pairing any electrons. Dr. Nahla Abdelshafi 13  Fall 2024 Model of the Atom Electron, Proton, Neutron. Electrons are –1, protons +1 and neutrons are neutral. Atoms have an equal number of electrons and protons they are electrically neutral Protons and neutrons make up the heavy, positive core, the NUCLEUS which occupies a small volume of the atom. Central Protons (positively charged) Nucleus Neutrons ( no charge) Moving in the Electrons (negatively charged) space around the nucleus The number of protons = the number of electrons, so the atom is neutral in charge. Dr. Nahla Abdelshafi 14  Fall 2024 Components of the atom An ion is an atom, or group of atoms, that has a net positive or negative charge. Cation + ion with a positive charge If a neutral atom loses one or more electrons ; it becomes a cation. Na atom -----------------Na+ ion + e- (11p+, 11e-) (11p+, 10 e-) Ca atom-------------------Ca2+ ion + 2e- (20p+, 20e-) (20p+, 18e-) Anion – ion with a negative charge If a neutral atom gains one or more electrons ; it becomes an anion. Cl atom + e- ----------------- Cl- ion (17p+, 17 e-) (17p+, 18 e-) O atom + 2e- ------------------ O2- ion (8p+, 8e-) (8p+, 10e-) Dr. Nahla Abdelshafi 15  Fall 2024 An ion Atom or molecule that is no longer neutral since it has lost or gained an electron. How do atoms bond? Atoms form bonds with other atoms using electrons in their outer energy level. What are the different ways atoms bond? Gain Electron (+) Lose Electron (-) Pooling Electron (together) Sharing Electron Dr. Nahla Abdelshafi 16  Fall 2024 IONIC BONDS- metal ion + nonmetal ion Ionic bond Chemical bonding holding oppositely charged ions together. Between a metal and non metal Responsible for gaining or losing electrons. Dr. Nahla Abdelshafi 17  Fall 2024 COVALENT BONDS IONIC BOND COVALENT BOND Covalent bond Share Electrons. Bond that forms between non metals only. Produce molecular compounds. Ex. Hydrogen Molecule Dr. Nahla Abdelshafi 18  Fall 2024 COVALENT BONDS When atoms share electrons, they don’t always share them equally. Nonpolar covalent compounds: share e- equally Will not conduct an electrical current at all All diatomic molecules are nonpolar Polar covalent compounds: share e- unequally Can conduct an electrical current Polarity affects how chemicals mix. “Like dissolves like.” Nonpolar compounds mix with other nonpolar compounds. Polar compounds mix with other polar compounds. Ex: water Nonpolar compounds will not mix with polar compounds. Dr. Nahla Abdelshafi 19  Fall 2024 Metallic Bonding: Bond between metal and another metal. Electrons in the outer energy level are not tightly held together----move freely (pooled) Electrons stick together Responsible for good conductivity, malleability and ductility. Dr. Nahla Abdelshafi 20  Fall 2024 Law of Conservation of Mass 1775 - Lavoisier “Father of Modern Chemistry” In every chemical operation an equal amount of matter exists before and after the operation. Mass is conserved, the total mass after the chemical operation must be the same as that before. Problem Potassium chlorate (KClO3) decomposes to potassium chloride (KCl) and oxygen (O2) when heated. In one experiment 100.0 g of KClO3 generated 36.9 g of O2 and 57.3 g of KCl. What mass of KClO3 remained unreacted? Mass of KClO3 before reaction = mass of KCl + mass of O2 + mass of unreacted KClO3 100.0 g of KClO3 = 57.3 g KCl + 36.9g O2 + g unreacted KClO3 g unreacted KClO3 = 100.0 g - 57.3 g - 36.9 g = 5.8 g Dr. Nahla Abdelshafi 21  Fall 2024 Law of Definite Proportions In a given chemical compound, the proportions by mass of the elements that compose it are fixed, regardless of the source of the compound. The ratio of elements in a compound is fixed regardless of the source of the compound. Water is made up of 11.1% by mass of hydrogen and 88.9% oxygen. Problem In a set of experiments very pure tin (Sn) was combined with bromine (Br) forming tin tetrabromide (SnBr4). Using the data below, confirm the law of definite proportions by calculating the % of tin in each sample of SnBr4. Dr. Nahla Abdelshafi 22  Fall 2024 Law of Definite Proportions Problem In a set of experiments very pure tin (Sn) was combined with bromine (Br) forming tin tetrabromide (SnBr4). Using the data below, confirm the law of definite proportions by calculating the % of tin in each sample of SnBr4. Grams of Sn reacted Grams of SnBr4 formed 2.8445 10.4914 = 7.6469 3.0125 11.1086 = 8.0961 4.5236 16.6752 = 12.1516 Need to determine (mass of Sn reacted) (mass of Sn reacted) (mass of Br reacted) (mass of Br reacted) Mass of Br reacted = Mass of SnBr4 formed - mass of Sn reacted 0.3721 0.3721 0.3723 Dr. Nahla Abdelshafi 23  Fall 2024 Chemical Reaction It is a chemical change in which one or more substances are destroyed and one or more new substances are created. BEFORE AFTER H2 gas H2O liquid and O2 gas Reactants → Products Reactants: Substances that are destroyed by the chemical change (bonds break). Products: Substances created by the chemical change (new bonds form). The arrow (→) is read as “yields”. Dr. Nahla Abdelshafi 24  Fall 2024 Other symbols in chemical reactions (s) = solid (l) = liquid (g) = gas (aq) = aqueous solution (the substance is dissolved in H2O) “+” separates two or more reactants or products “→” yield sign separates reactants from products Evidence for a Chemical Reaction 1) Evolution of light or heat. 2) Temperature change (increase or decrease) to the surroundings. 3) Formation of a gas (bubbling or an odor) other than boiling. 4) Color change (due to the formation of a new substance). 5) Formation of a precipitate (a new solid forms) from the reaction of two aqueous solutions. Dr. Nahla Abdelshafi 25  Fall 2024 Translating Word Equations to Skeleton Equations A skeleton equation uses chemical formulas rather than words to identify the reactants and products of a chemical reaction. The word equation Iron (s) + chlorine (g) → iron (III) chloride (s) The skeleton equation Fe(s) + Cl2(g) → FeCl3 (s) A skeleton equation is not yet “balanced” by coefficients! Dr. Nahla Abdelshafi 26  Fall 2024 Translating Word Equations to Skeleton Equations 6 Na (s) + Fe2O3 (s) → 3 Na2O (s) + 2 Fe (s) The numbers preceding the chemical formulae are coefficients. They are used to balance the reaction. The numbers within the chemical formulae are subscripts. You can read the above balanced reaction as: “6 atoms of solid sodium plus 1 formula unit of solid iron (III) oxide yields 3 formula units of solid sodium oxide and 2 atoms of solid iron” or… “6 moles of solid sodium plus 1 mole of solid iron (III) oxide yields 3 moles of solid sodium oxide plus 2 moles of solid iron” Chemical reactions can never be read in terms of grams, only in terms of particles or groups of particles (moles). Dr. Nahla Abdelshafi 27  Fall 2024 Conservation of Mass During a chemical reaction, atoms are neither created nor destroyed (Conservation of Mass). Hydrogen and oxygen gas react to form water: H2 (g) + O2 (g) → H2O (l) H2 (g) + O2 (g) → H2O (l) What is wrong with this equation above? Doesn’t it appear that one oxygen atom “went missing”? According to conservation of mass, the proper way to write this reaction is: 2H2 (g) + 1O2 (g) → 2H2O (l) The red coefficients represent the # of molecules (or the # of moles) of each reactant or product. Dr. Nahla Abdelshafi 28  Fall 2024 Types of Chemical Reactions The five types of chemical reactions we will discuss are: Combination/Synthesis: Two or more substances combine to form one substance. Decomposition: One substance reacts to form two or more substances. Single Displacement : A metal replaces a metal ion (or H+) in a compound Ni + 2AgNO3 → 2Ag + Ni(NO3)2 Double Displacement: Ions of two compounds exchange places with each other. 2NaOH + CuSO4 → Na2SO4 + Cu(OH)2 Combustion: When a substance combines with oxygen, a combustion reaction results. Combination/Synthesis Decomposition Single Displacement Double Displacement Dr. Nahla Abdelshafi 29  Fall 2024 The Mole It is the international system of units of the amount of substance. 1 mole = 6.022 x 1023 particles Avogadro’s number Examples: 1 mole of Na atom = 6.022 x 1023 atoms. 1 mole of H2O molecule = 6.022 x 1023 molecules. 1 mole of K+ ion = 6.022 x 1023 ions. The mass of 1 mole of an element is equal to its Molar mass in grams. 1 mole of substance = Molar mass (g/mol) If an element, Molar mass= Atomic mass. Examples: 1 mole of Na atom = 22.99 g/mol. 1 mole of H atom = 1.008 g/mol. If a molecule, Molar mass= Molecular mass. Molecular Weight Examples: 1 mole of H2O molecule= 18.016 g/mol. Dr. Nahla Abdelshafi 30  Fall 2024 The Mole How to calculate the molar mass of a molecule? Molar mass of methane (CH4): 1 mole of CH4 molecule = 12.01 + (4 x 1.008) = 16.04 g/mol Molar mass of aspirin (C9H8O4) 1 mole of C9H8O4 molecule = (9 x 12.01) + (8 x 1.008) + (4x16) = 180.15 g/mol Mass of m/M Number of moles nNA Number of atoms element (m) of element (n) of elements (N) n.M N/NA Dr. Nahla Abdelshafi 31  Fall 2024 The Mole Example 1: How many KCl molecules are present in 3 moles of KCl? 1 mole of KCl ------------ 6.022 x 1023 molecules 3 moles of KCl ------------ ?? Molecules Number of molecules = 1.8 x 1024 molecules Example 2: How many moles of juglone C10H6O3 are found in a 1.56x10-2 g sample of pure dye? Molar mass of C10H6O3 =[(10 x 12.01) + (6 x 1.008) + (3 x 16.00)] = 174.1 g 1 mole of C10H6O3------------ Molar Mass of C10H6O3 1 mol juglone--------------------------174.1 g/mol ? mol------------------------------------- 1.56x10-2 g No. of moles of jug lone is [1.56x10-2 x 1]/174.1 = 8.96x10-5 mol juglone. Dr. Nahla Abdelshafi 32  Fall 2024 Composition of compounds n x Molar mass of element % Composition of an element = Molar mass of compound x 100 Example 1: Calculate the mass percent of each element in Water (H2O). Mass of H = 2 x 1.008 = 2.016 g Mass of O = 1 x 16.00 = 16.00 g Molar Mass of 1 mole (H2O) = 18.016 g/mole So the mass percent of each component will be: Mass percent of H = (2.016/18.016) x 100 = 11.19 % Mass percent of O = (16.00/18.016) x 100 = 88.81% Dr. Nahla Abdelshafi 33  Fall 2024 Composition of compounds Example 2: Carvone is a substance with the molecular formula (C10H14O), calculate the mass percent of each element in carvone. Mass of C = 10 x 12.01 = 120.01 g Mass of H = 14 x 1.008 = 14.11 g Mass of O = 1 x 16.00 = 16.00 g Mass of 1 mol (C10H14O) = 120.01 + 14.11 + 16.00 = 150.2g So the mass percent of each component will be: Mass percent of C= 120.1/150.2 x 100 = 79.96% Mass percent of H = 14.11/150.2 x 100 = 9.394% Mass percent of O = 16.00/150.2 x 100 = 10.65% Dr. Nahla Abdelshafi 34  Fall 2024 References 6.2-Essential books 6.2.1. B.S. Bahl, G.D. Tuli, A. Bahl, “The Essentials of Physical Chemistry” S Chand & Co, 28th edition (revised edition), (2019). 6.2.2. G. Svehla, “Vogel,s Qualitative Inorganic Analysis", Pearson Education, 7th edition, (2012). 6.3-Recommended books 6.3.1. R. Chang, K. A. Goldsby, “General chemistry (the essential concepts)”, McGraw Hill, 7th edition, (2013). 6.3.2. D. A. Skoog, D. M. West, F. J. Holler, S. R. Crouch, “Fundamentals of Analytical Chemistry”, 9th Edition, Cengage Learning, (2013). Office: 225 Tuesday: 10 AM – 12 PM Dr. Nahla Abdelshafi 35