chem L1.pdf

Introduction to Chemistry Chemistry: The science that deals with the structure and behavior of matter. Scientific Method: An essential part of understanding and applying chemistry principles. SI Base Units: Length: Meter (m) Mass: Kilogram (kg) Tim...

Introduction to Chemistry Chemistry: The science that deals with the structure and behavior of matter. Scientific Method: An essential part of understanding and applying chemistry principles. SI Base Units: Length: Meter (m) Mass: Kilogram (kg) Time: Second (s) Temperature: Kelvin (K) Derived Units: 1 Liter (L) = \( 10^{3} \) cubic meters (m³) Metric Prefixes: Used to express large or small quantities, e.g., giga (G), mega (M), kilo (k), centi (c), milli (m), micro (µ), nano (n), pico (p). Scientific Notation: A method to express large or small numbers using a coefficient and an exponential term (e.g., \( 5.5 \times 10^{21} \)). Uncertainty in Measurements: The coefficient in scientific notation reflects the uncertainty of a number. Assumed uncertainty is plus or minus one in the last reported position unless otherwise stated. Conversion to Scientific Notation: Move the decimal to create a single nonzero digit to the left. The number of positions moved determines the exponent. Scientific Notation to Decimal: Shift the decimal based on the exponent's value (right if positive, left if negative). Benefits of Scientific Notation: Convenience for expressing very large or small numbers. Clear reporting of uncertainty in measurements. Operations with Exponential Terms: Multiplying: Add exponents. Dividing: Subtract exponents. Raising to a power: Multiply exponents. Mass vs. Weight: Mass: A measure of the amount of matter, constant regardless of location. Weight: A measure of gravitational attraction, varies with location. Precision and Accuracy: Precision: How closely measurements resemble each other. Accuracy: How close a measurement is to the true value. Reporting Measurements: Report all certain digits and one estimated (uncertain) digit. Use scientific conventions for rounding numbers in digital readouts.  The Structure of Matter and the Chemical Elements Scientific Models: Simplified approximations of reality. Useful representations for understanding complex systems. Kinetic Molecular Theory: All matter is composed of tiny particles in constant motion. Temperature increase = increased particle motion. Solids, liquids, and gases differ in particle freedom and attraction strength. States of Matter: Solids: Constant shape and volume; particles are trapped in a cage formed by strong attractions. Liquids: Constant volume, variable shape; particles move freely, breaking and reforming attractions. Gasses: Variable shape and volume; particles are far apart, with little attraction between them. Matter Composition: Elements: 118 known; 83 are stable and found in nature. Metals, Nonmetals, and Metalloids: Classified by properties like luster, conductivity, and malleability. Atoms: Tiny, about \(10^{10}\) meters in diameter. Composed of protons (+ charge), neutrons (neutral), and electrons ( charge). Ions: Charged particles formed by the loss (cation) or gain (anion) of electrons. Isotopes: Atoms of the same element with different numbers of neutrons. Examples include hydrogen isotopes: Protium, Deuterium, and Tritium. Periodic Table: Organized by groups and periods, highlighting relationships between elements (e.g., alkali metals, noble gasses). Properties of Metallic Elements: Shiny luster, good heat, and electrical conductors. Malleable and can be hammered into sheets. Molecular Structure of Nonmetals: Exist as atoms, diatomic molecules (e.g., H₂, O₂), or complex molecules (e.g., S₈, C (diamond)). Chemical Changes: Electrons are primarily responsible, as they can be gained, lost, or shared in reactions. Protons determine the number of electrons in uncharged atoms. Artificial Elements: Elements 113 and 115 were created in a lab setting through bombardment of specific atoms.  Research on these elements supports theories of matter's nature and has potential medical applications.  Good Laboratory Practices and Chemical Safety Good Laboratory Practices (GLP): Guidelines for safe and proper work in laboratories (commercial, university, government, industrial). Includes training, equipment care, sample handling, analysis, data recording, and reporting. Major Goal: Ensure results are a valid representation of a sample by following proper procedures at every step. Standard Operating Procedures (SOPs): Written instructions for safely performing tasks with hazardous materials or operations. In teaching labs, SOPs describe experiments provided by instructors. Must be clear, specific, and easily understood. Laboratory Safety: Safe execution of experiments is crucial. Laboratories often handle small quantities of chemicals, minimizing hazards. Components include well designed work areas, safety equipment, and trained personnel. Common Laboratory Safety Features: Safety showers, eye washes, exits, emergency phones, fire extinguishers, first aid kits, spill handling equipment, and proper facilities for chemical handling and storage. Identifying Chemical Hazards: Essential to adopt appropriate handling methods. Physical Hazards: Explosive, flammable, or highly reactive chemicals. Health Hazards: Toxic, corrosive, carcinogenic, or damaging to specific body parts. Chemical Hazard Symbols and Labels: Mandatory for manufacturers, distributors, and importers to indicate dangers using words, pictures, or symbols. Globally Harmonized System (GHS): An international system for classifying and labeling chemicals to ensure consistent hazard information worldwide. Involves hazard classification, labeling, and Safety Data Sheets (SDS). Material Safety Data Sheets (MSDS): Provide detailed information on chemical hazards, exposure effects, handling, storage, disposal, and emergency measures. Must be accessible in hard copy or electronically. Proper Handling of Chemicals: Minimizing Exposure: Use ventilation hoods, wear protective gear, and avoid direct skin contact. Chemical Storage: Store chemicals to avoid hazards or interactions, keeping reactive chemicals separate. Labeling Chemical Containers: Include the chemical's name, preparation date, and preparer's name. Proper labels prevent mixups and aid in proper disposal. Chemical Disposal: Dispose of chemicals following environmental and legal requirements. Separate chemicals by reactivity and composition for proper disposal. Routes of Chemical Entry into the Body: Inhalation: Use ventilation hoods to reduce exposure to gases and volatile substances. Skin Contact: Use protective clothing, gloves, and cover cuts/abrasions. Ingestion: Avoid eating, drinking, or applying cosmetics in the lab. Injection: Carefully use sharp objects and dispose of them in labeled "SHARPS" containers.