Pharmaceutical Analytical Chemistry 1 Lecture Notes PDF

Pharmaceutical analytical chemistry 1 Prepared by Staff members of Analytical Chemistry Department  States of matter Solid Liquid Gas Table (1):Different characteristics of matter. Character...

Pharmaceutical analytical chemistry 1 Prepared by Staff members of Analytical Chemistry Department  States of matter Solid Liquid Gas Table (1):Different characteristics of matter. Character Solid Liquid Gas Particle Packed close in a regular Packed close in an Arranged arrangement arrangement irregular arrangement totally irregular Shape and Fixed shape and volume No fixed shape but No fixed shape volume fixed volume and volume Motion of No freely motion but Move around past Move randomly particles vibrate in its positions each other Ability to No compression Little Easy compress 1  1. Matter properties and measurements ❑ All properties of matters are either physical or chemical properties. ❑ Chemical property is any characteristic that can be determined with change in chemical structure. ❑ Physical property is any characteristic that can be determined only by change substance’s molecular structure (don’t alter chemical structure of substance). ❑ Physical properties either extensive or intensive. ❑ Extensive properties are that depend on amount of matter to be measured such as mass and volume. 2  Matter properties and measurements (Cont.) ❑ Intensive properties are that not depend on amount of matter to be measured such as color, taste and density. ❑ Physical properties include: 1. Color (intensive). 2. Density (intensive). 3. Volume (extensive). 4. Mass (extensive). 5. Boiling point (intensive): temperature at which substance boils. 6. Melting point (intensive): temperature at which substance melts. 3  Chemical properties Chemical property is that property leads to change in substance’s chemical structure. Examples of chemical properties: A. Heat of combustion (∆Hc): Energy released upon complete combustion (burning) of compound with oxygen. B. Stability: refers to reactions the alter chemical structures of compounds such as oxidation (reaction with oxygen), hydrolysis (reaction with water) and photosensitivity (decomposition by light). 4  Chemical properties (Cont.) C. Flammability: ability of compound to burn when exposed to flame. Commonly high temperature in presence of oxygen. D. Oxidation-Reduction: oxidation refers to loss of electrons while reduction is gain of electrons. Chemical change or chemical reaction: process that cause a substance to change into a new substance with a new chemical formula. A+B (reactants) C (product) 5  Units of measurement ❑ International system of units (SI): metric system measurement used in science, medicine and industry. ❑ There are seven basic units in SI system: 1. Kilogram (Kg): unit of mass 2. Second (S): unit of time 3. Kelvin (K): unit of temperature 4. Ampere (A): unit of electricity 5. Mole (mol): amount of substance 6. Candela (cd): unit of luminous intensity (measure of the wavelength- weighted power emitted by a light source). 7. Meter (m): Unit of length. 6  Basic SI units Table (2): Different basic units of SI system. Quantity Dimension Unit name Unit symbol Quantity name symbol symbol meter m length l, x, r L Kilogram kg mass m M second s time t T ampere A electric current I I thermodynamic kelvin K T Θ temperature candela cd luminous intensity Iv J mole mol amount of substance n N 7  Prefix for SI units Table (3): Standard prefixes for SI units of measure. 8  Relationship between density and volume ✓ The volume of substance related to quantity of substance at definite pressure and temperature. ✓ The volume of substance can be measured in volumetric or graduated measurements. ✓ Density is the amount of substance contained in a definite volume ✓ Density is used to define any substance. ρ (rho)= m/v where m is mass v is volume ✓ The density of a material varies with temperature and pressure. 9 ✓ This variation is typically small for solids and liquids but much greater for gases. ✓ Increasing the pressure on an object decreases the volume of the object and thus increases its density. ✓ Increasing the temperature of a substances decreases its density by increasing its volume. ✓ Increasing mass will increase density except water is unusual case where its solidification (ice) becomes lighter than liquid state (water) and floats. ✓ Specific gravity is ratio between density of substance to density of reference material (water) at constant volume. 10 Table (4): Different densities of water at different degrees. The density of water at constant pressure Temp (ºC) Density (kg/m3) 100 958.4 25 997.0479 0 999.8395 −30 983.854 11  Measurement tools Accurate (volumetric) Rough (graduated) ❑ Volumetric pipette Beaker ❑ Volumetric flask Graduated pipette ❑ Burette 12 Volumetric pipette Volumetric flasks Burette Beaker Graduated pipette 13  Temperature measurement Measurement of temperature should be against accepted standards. Temperature can be measured in several scales as Celsius, Kelvin and Fahrenheit. Temperature is a measure of cold or heat and measured by Thermometer. 14 Table (5): Calculation of temperature by various scales. 15  Conversion to and from Celsius degree Table (6): Conversion of Celsius degree to Kelvin and vice versa. 16  Dimensional analysis (unit conversion) A method of converting one unit to another. List of some commonly derived units: Term Definition Unit Area Quantity that expresses the extent of a two- m2 dimensional Volume quantity of three-dimensional space enclosed by a m3 closed surface Velocity Distance taken by object to move to another place m/s with respect Acceleration Rate of change of velocity of an object with respect m/s2 to time Density Substance mass per unit volume G/ml or G/cm3 Force Strength that cause an object with mass to change Newton or its velocity kg·m/s2 Energy Force that must be supplied to an object in order to Joule or move a certain distance. kg m2 s−2 17  Converting between moles and grams ❖ In order to convert the moles of a substance to grams, you will need to multiply the mole value of the substance by its molar mass. No. of moles= no. of grams/molar mass Molar mass= x grams/1mole 1. How many grams are in 3.79 moles of calcium bromide, CaBr2? (M.wt= 199.88) Answer 3.79×199.88/1 mole= 758 grams CaBr2 18 2. How many grams are in 0.572 moles of glucose, C6H12O6? [ C=12, O= 16 and H=1] Answer Molecular weight= 12×6+ 12×1+ 16×6= 180 g/mol No. of grams= 0.572×180/1mol= 102.96 g C6H12O6 19