organic chemistry complete (pre-board review 2014)

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  • 1.Refresher Course on Organic Chemistry and Organic Medicinal Chemistry Mr. Jan Dominique R. Lapig, RPh. April May 2014

2. Part I: General Chemistry 3. The Study of Chemistry What is Chemistry? Chemistry is the study of the properties and behavior of matter. Science of the composition of matter and changes in composition it may undergo either spontaneously or because of intentionally established environmental condition. Matter anything that occupies space and has mass. 4. Role of Chemistry in Modern Life Biological molecules Biochemical processes (cell whole organism) Medicines (Inorganic and Organic, Natural and semi-synthetic) eg: Aspirin Drug discovery and development (Physicochemical properties, ADME) 5. Classification of Matter The basic difference between these states is the distance between the bodies. Gas bodies are far apart and in rapid motion. Liquid bodies closer together, but still able to move past each other. Solid bodies are closer still and are now held in place in a definite arrangement. 6. Classification of Matter 7. Pure Substances and Mixtures Mixture combination of two or more substances in which each substance retains its own chemical identity. Homogeneous mixture composition of this mixture is consistent throughout. Solution: example syrup Heterogeneous mixture composition of this mixture varies throughout the mixture. Classification of Matter 8. Separation of Mixtures Mixtures can be separated by physical means. Filtration Chromatography Distillation Classification of Matter 9. Separation of Mixtures Classification of Matter 10. Pure Substances and Mixtures It is also possible for a homogeneous substance to be composed of a single substance pure substance. Element A substance that can not be separated into simpler substances by chemical means. Atom the smallest unit of an element that retains a substances chemical activity. Classification of Matter 11. Elements There are ____ elements known. Each element is given a unique chemical symbol (one or two letters). C, N, Hg, Au, Mn Notice that the two letter symbols are always capital letter then lower case letter because: CO carbon and oxygen Co element cobalt Classification of Matter 12. Compound: a substance composed of two or more elements united chemically in definite proportions. The proportions of elements in compounds are the same irrespective of how the compound was formed. Law of Constant Composition (or Law of Definite Proportions): The composition of a pure compound is always the same, regardless of its source. Classification of Matter 13. Properties of Matter Physical and Chemical Property Physical Property a property that can be measured without changing the identity of the substance. Example: melting point, boiling point, color, odor, density Chemical Property: those that determine how a substance can be converted to another substance. 14. Physical and Chemical Property Intensive properties independent of sample size. Like temperature, refractive index, density, hardness. Extensive properties depends on the quantity of the sample (sample size). Like mass and volume Properties of Matter 15. Physical and Chemical Changes Physical change: the change in the physical properties of a substance. Physical appearance changes, but the substances identity does not. Water (ice) Water (liquid) Properties of Matter 16. Physical and Chemical Changes Chemical change: (chemical reaction) the transformation of a substance into a chemically different substance. When pure hydrogen and pure oxygen react completely, they form pure water. 2H2 + O2 2H2O Properties of Matter 17. Physical and Chemical Changes Properties of Matter 18. Physical Properties of Drug Molecule Physical States: Amorphous solid Crystalline solid Hygroscopic solid Liquid Gas 19. Physical Properties of Drug Molecule Melting point: temperature at which a solid becomes a liquid. Importance of melting point? Water (0C, 100C) Eutectic mixture Packing: property of a solid; is a property that determines how well the individual molecules in a solid fit together in a crystal lattice 20. Physical Properties of Drug Molecule Boiling point: temperature at which the vapor pressure of the liquid is equal to the atmospheric pressure 21. Physical Properties of Drug Molecule Polarity: is a physical property of a compound, which relates other physical properties, e.g. melting and boiling points, solubility and intermolecular interactions between molecules Bond polarity: is used to describe the sharing of electrons between atoms. 22. Physical Properties of Drug Molecule Solubility: is the amount of a solute that can be dissolved in a specic solvent under given conditions. Solute Solvent Solvation/hydration 23. Physical Properties of Drug Molecule Unsaturated solution Saturated solution Supersaturated solution Other definition of solubility: the maximum equilibrium amount of solute that can usually dissolve per amount of solvent 24. Physical Properties of Drug Molecule Rate of Solution: is a measure of how fast a solute dissolves in a solvent. Depends on some properties like particle size, stirring, temperature and concentration 25. Acid-base properties and pH 26. Acid-base properties and pH Arrhenius acids and bases Acid: a substance that produces hydronium ion Base: a substance that produces hydroxide ion Neutralization reaction Brnsted-Lowry acids and bases Acid: proton donor Base: proton acceptor 27. Acid-base properties and pH Lewis acid: employ an electron lone pair from another molecule in completing the stable group of one of its own atoms. aka aprotic acid Lewis base: any species that donates a pair of electrons to a Lewis acid to form a Lewis adduct. For example, OH and NH3 are Lewis bases, because they can donate a lone pair of electrons. 28. pH and pKa values pH: is dened as the negative of the logarithm to base 10 of the concentration of the hydrogen ion. The acidity or basicity of a substance is dened most typically by the pH value. What is the pH of water? Blood plasma? Stomach? 29. pH and pKa values pH - widely used method of expressing the hydrogen ion concentration of dilute acids, bases & neutral solutions in terms of pH. pH is a mathematical definition of H+ that involves a numerical scale that runs from 0 - 14. It is the negative logarithm of the hydrogen ion. pH = 1 or pH = - log [H+] log [H+] 30. Sample Problem The H+ concentration of an unknown liquid is 1 x 10-7 mole/L at 25C. What is the formula to be use? Show the complete solution. What is the pH of the unknown? What is the unknown substance? 31. pOH Although rarely used, the hydrogen ion (OH) concentration can be expressed as pOH, which is the negative logarithm of the hydroxide ion concentration or: pOH = 1 or pOH = - log [OH-] log [OH-] 32. Sample Problem Compute for the pOH and pH of the solution if the OH- concentration is 12.1 x 10-10. Given: pOH = 9.10, find OH- concentration. 33. pH and pKa values Ka: is a quantitative measure of the strength of an acid in solution. Very strong acids pKa < 1 Moderately strong acids pKa = 1-5 Weak acids pKa = 5-15 Extremely weak acids pKa> 15 34. Buffer Buffers is a solution in which the pH of the solution is "resistant" to small additions of either a strong acid or strong base. Composed of a weak acid and its conjugate base (e.g. CH3COOH and CH3COO-) or a weak base and its conjugate acid (e.g. NH3 and NH4 +). Ex: Blood Buffer capacity 35. Acid-base titration: Neutralization Titration: The process of obtaining quantitative information on a sample using a fast chemical reaction by reacting with a certain volume of reactant whose concentration is known. aka _____________________ Titrant: the known solution is added from a buret to a known quantity of the analyte until the reaction is complete Endpoint: point at which the reaction is observed to be completed 36. Units of Measurement m/s seconds meters timeofunits distanceofunits velocityofUnits SI Units There are two types of units: fundamental (or base) units; derived units There are 7 base units in the SI system. Derived units are obtained from the 7 base SI units. 37. Units of Measurement SI Units 38. Units of Measurement SI Units 39. Temperature Units of Measurement 40. Units of Measurement Temperature Kelvin Scale Same temperature increment as Celsius scale Lowest temperature possible (absolute zero) is zero K. Absolute zero: 0 K = -273.15oC Celsius Scale Water freezes at 0oC and boils at 100oC. To convert: K = oC + 273.15 Fahrenheit Scale Not generally used in science. Water freezes at 32oF and boils at 212oF 41. Temperature Converting between Celsius and Fahrenheit Sample problem. Convert the following: 1. 257F to C 2. 75C to F and K 32-F 9 5 C 32C 5 9 F Units of Measurement 42. Volume The units for volume are given by (units of length)3. i.e., SI unit for volume is 1 m3 A more common volume unit is the liter (L) 1 L = 1 dm3 = 1000 cm3 = 1000 mL We usually use 1 mL = 1 cm3 Units of Measurement 43. Mass Mass is the measure of the amount of material in an object. This is not the same as weight which is dependent on gravity. Units of Measurement 44. All scientific measures are subject to error. These errors are reflected in the number of figures reported for the measurement. These errors are also reflected in the observation that two successive measures of the same quantity are different. Uncertainty in Measurement 45. Precision and Accuracy Measurements that are close to the correct value are accurate. Measurements which are close to each other are precise. Measurements can be: accurate and precise precise but inaccurate neither accurate nor precise Uncertainty in Measurement 46. Precision and Accuracy Uncertainty in Measurement 47. Uncertainty in Measurement Significant Figures - The number of digits reported in a measurement reflect the acc