Pharmaceutical Analytical Chemistry I 2024-2025 Lecture 1 PDF

10/1/2024 1 Pharmaceutical Analytical Chemistry Department Faculty of Pharmacy Assiut University 2024/2025 2 1 ...

10/1/2024 1 Pharmaceutical Analytical Chemistry Department Faculty of Pharmacy Assiut University 2024/2025 2 1  10/1/2024 Contents 1- States of matter-Units of measurement, Temperature measurement, Atomic structure. 2- Types of bonds (Ionic bond, Covalent bonds, Coordinate bond, Metallic bond, Hydrogen bond, Inter- and intra-molecular hydrogen bonds). 3-Stoichiometry of chemical reactions , Electromagnetic spectrum. 4- Different gas laws, Real gas and ideal gas, diffusion vs. effusion of gases. 5- Real reactions in aqueous solutions, Reversible reactions- Irreversible reactions , equilibrium constant and its calculation. 6- Kinetics of chemical reactions- Rate of chemical reactions &Types of rate Collision theory , factors affecting reaction rate , Order of the reaction. 7- Acid- Base theory 3 3 Lecture No. 1 Presented by Prof. Dr. Samia El-Gizawy Dr. Noha Mostafa Hosny Group A & B Group C Pharmaceutical Analytical Chemistry Department Faculty of Pharmacy Assiut University 2024-2025 4 2  10/1/2024 Introduction 5 5 What is Matter in Chemistry? Matter is the substances that have their own mass and volume. The matter is made up of very tiny particles that we cannot see them with naked eyes. It has been observed that matter exists in nature in different forms: 1- Some substances are rigid and have a fixed shape like wood and stone; 2- Some substances can flow and take the shape of their container like water, 3- Some do not have definite shape or size like air. 6 6 3  10/1/2024 States of Matter ▪ The three distinct physical forms that matter can take in environments: solid, liquid, and gas. ▪ But, scientists have identified SIX physical states of matter: 1. solids, 2. liquids, 3. gases, 4. plasmas, 5. Bose-Einstein condensate (BEC) 6. Neutron stars. 7 7 States of Matter 1- Solid 2- Liquid 3- Gas Character Solid Liquid Gas Particle Packed close in a regular Packed close in an Arranged arrangement arrangement irregular arrangement totally irregular Shape Fixed shape and volume No fixed shape but No fixed shape fixed volume and volume Motion of No freely motion but Move around past Move particles vibrate in its positions each other randomly Ability to No compression Little Easy compress Examples Ice, Sugar, Rock Water, Milk, Blood Air, Oxygen 8 8 4  10/1/2024 Interconversion Between States of Matter 9 9 States of Matter 4- PLASMAS: ▪ Like gases, plasmas have no fixed shape or volume, and are less dense than solids or liquids. ▪ Unlike ordinary gases, plasmas are made up of atoms in which some or all electrons have been lost and positively charged nuclei, called ions, move freely. How are plasma formed? A gas is usually converted to a plasma in one of two ways: 1- From a huge voltage difference between two points 2- By exposing gases to extremely high temperatures Heating matter to high temperatures results in electrons leaving the atoms which further results in the presence of free electrons. These methods creates a so-called partially ionized plasma. 10 10 5  10/1/2024 Interconversion Between States of Matter 11 11 12 12 6  10/1/2024 Can Water Converted into Plasma? 13 13 States of Matter 5- Bose-Einstein Condensate (BEC): The BEC is a state of matter that occurs at extremely low temperatures, near absolute zero (0 K or -273.15°C). ▪ BEC formed when atoms start to get cold. ▪ The cold atoms get closer and clump up. ▪ Then, they look like a big blob. Some examples of materials that can form BECs include: ✓ Helium: can form a BEC at temperatures below (-270.98°C). ✓ Sodium atoms: can form a BEC at temperatures below (-273.14°C). ✓ German scientists produce first Bose-Einstein condensate with calcium atoms at extremely low temperatures close to (-273.15 °C) 14 14 7  10/1/2024 States of Matter 6- Neutron Stars: Neutron stars are created when massive stars reach the ends of their lives and are composed of the densest matter in the known universe. 15 15 Matter Properties and Measurements 16 16 8  10/1/2024 Matter Properties and Measurements ▪ All properties of matters are classified into: ❑ Chemical property is any characteristic that can be determined with change the identity of the substance. ❑ Physical property is any characteristic that can be determined without change the identity of the substance. ▪ Physical properties either: ✓ Extensive properties are that depend on amount of matter to be measured such as mass and volume. ✓ Intensive properties are that not depend on amount of matter to be measured such as color, taste and density. 17 17 Physical Properties of Matter 1. Color (intensive). 2. Density (intensive). 3. Volume (extensive). 4. Mass (extensive). 5. Boiling point (intensive): temperature at which substance boils. 18 6. Melting point (intensive): temperature at which substance melts. 18 9  10/1/2024 Chemical Properties of Matter Chemical property is that property leads to change in substance’s chemical structure. Examples of chemical properties: A. Heat of combustion (∆H): Energy released upon complete combustion (burning) of compound with oxygen. B. Stability: refers to reactions that alter chemical structures of compounds *such as oxidation (reaction with oxygen), hydrolysis (reaction with water) and photosensitivity (decomposition by light). 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. 19 19 Chemical Properties of Matter 20 20 10  10/1/2024 Physical vs Chemical Changes of Matter Chemical change – a process in which chemical bonds are broken or created to make a new substance. A+B (reactants) → C (product) Physical change – a process in which a substance changes its state of matter, but chemical bonds stay intact. 21 21 Physical vs Chemical Changes of Matter 22 22 11  10/1/2024 23 24 24 12  10/1/2024 Units of Measurements ▪ The units of measurement are the units that are used to represent physical quantities like length, mass, temperature, current, area, volume, intensity ▪ SI units: ✓ comes from the original French name, Système international d'unités. ✓ are units of the international system of units known as the metric system ✓ used across the world and each unit has a standard measure. ▪ Imperial Units of Measurement: Physical Quantity Imperial Units ✓ Measures used in Great Britain. Length foot, inch, yard, mile ✓ Unlike metric units, the imperial system Mass ounce, pound, stone, ton gallon, pint, quart, fluid uses different units to measure the physical Capacity ounce quantities like length. Note: The imperial units of measurement can be expressed in terms of the 25 metric units and vice-versa as they are standard units. 25 What are the 7 Basic IS Units of Measurement? 26 26 13  10/1/2024 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 (ρ, rho) is the amount of substance contained in a definite volume. ✓ Density is expressed in grams per cubic centimeter (g/cm3) ✓ Density is used to define any substance. ✓ The density of a material varies with temperature and pressure. ✓ This variation is typically small for solids and liquids but much greater for gases. 27 27 Relationship Between Density and Volume ✓ 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. Specific Gravitysubstance = ρsubstance / ρreference 28 If a material has a specific gravity less than 1, it will float on water. 28 14  10/1/2024 Relationship Between Density and Volume The density of water at Densities of Common Substances constant pressure Density at 25 Density at 25 Substance Substance Density °C (g/cm3) °C (g/cm3) Temp (ºC) (kg/m3) blood 1.035 corn oil 0.922 body fat 0.918 mayonnaise 0.910 100 958.4 whole milk 1.030 honey 1.420 25 997.0479 0 999.8395 −30 983.854 Water and oil: Since the oil has a lower 29 density than water, it floats on top. 29 Measurement Units of Temperature Temperature is a physical quantity that describes how hot or cold an object or the weather is and measured by Thermometer. Temperature can be measured in several scales as Celsius, Kelvin. and Fahrenheit. Kelvin is the SI unit of measuring temperature. ❑ Absolute zero (0 K) is temperature at which the particles in a substance are essentially motionless. [absolute zero is impossible to reach] 30 30 15  10/1/2024 LIGHT AND RADIATION 31 31 Light and Radiation Light is an electromagnetic radiation (EM), composed of both electric and magnetic components. It displays the property of continuous waves and can be described by the characteristics of wave motion. Light also behaves like a particle. Today, we envision light as a self-contained packet of energy, a photon, which has both wave and particle like properties. 32 32 16  10/1/2024 Light and Radiation Light waves, propagate at the highest known velocity of 300.000 Km/Sec. Such wave motion may be classified according to: 1- Wavelength (, lambda) which is the linear distance measured along the line of propagation, between crest of one wave to that of the next wave 2- Amplitude which is the vertical distance from midline of a wave to the peak or trough. 3- Frequency (, nu) is the number of waves that pass through a particular point in 1 second (Hz = 1 cycle/s) 4- Wavenumber (-, nu par), which is expressed in cm-1. When the wavelength () is expressed in cm, 1/ gives the number of waves per cm or wavenumber (-)= 1/ , cm-1 33 33 Relations between , and − ❑ Relations between , and - are given by the following equations: C=x Since - = 1/ Then - = 1/ = /C Or C = / - → Where C is the velocity of light in vacuum = 3 x 1010 cm/Sec. Note that: the longer the wavelength, the lower the frequency and the smaller the wavenumber and vice versa. ❑ The energy (E) of a photon is directly proportional to the frequency and inversely proportional to the wavelength. ❑ It can be related to C,  and by the following equation: E = h = h C/ → Where h is a constant called Planck’s constant , which equal to 34 6.625 x 10-27 erg. sec or 6.625 X 10-34 J.sec 34 17  10/1/2024 Relations between , and − Problem: Calculate wavenumber, frequency & energy if we have a visible radiation of 500 nm.  in cm = 500 ÷ 107 = 5 x 10-5 cm - = 1/ = 1/5 x 10-5 = 0.2 x 105 = 2 x 104 cm-1 = C X - = (3 x 1010) X (2 x 104) = 6 x 1014 s-1 E = h = (6.626 x 10-27 erg.s) X (6 x 1014 s-1) = 4.0 x 10-12 erg Different units of length are used to express wavelengths and their amplitude in different parts of the EM-spectrum. For example; In UV-Visible region, the units used are A0(Angstrom) and nm (nanometer), while in infra red region the units are the m (micron). Thus 1 m = 102 cm = 103 mm = 106 m = 109 nm = 1010 o. or 0 = 10-1 nm = 10-4 m = 10-7 mm = 10-8 cm = 10-10 m. x103 100 ÷104 0.1 mm 0.01 cm m 35 35 Electromagnetic Spectum ❑ Electromagnetic spectrum: is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. ❑ Electromagnetic radiation can be divided into various regions according to wavelength, wavenumber or frequency. ❑ There are many regions useful for analysis such as x-ray, UV-Visible, infrared, radio wave, microwave and more…. ❑ Radio waves have lowest energy (higher ). ❑ Cosmic rays have highest energy (lower ). 36 36 18  10/1/2024 How Light Interacts with Matter? Light ▪ By three ways: 1- Absorption 2- Reflection Matter 3- Transmission ▪ Interaction between matter and light occurs in the form of: ✓ Electronic excitation, ✓ Vibration of bonds, ✓ Rotation of nuclei. 37 37 38 38 19