Modern Chemistry - Matter and Change Notes

Overview of Chemistry as a Physical Science

• Chemistry is defined as the study of the composition, structure, and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes.

• Chemistry seeks to answer fundamental questions regarding how substances are composed, how they react, and why they behave in specific ways.

• The Natural Sciences are divided into two primary categories:

  1. Biological Sciences

  2. Physical Sciences

• Instruments are used to extend human senses and allow for measurements beyond the limits of natural perception:

  • Balances are utilized to measure the mass of materials.

  • Specialized microscopes are used to view structures as small as DNA.

Branches of Chemistry and Professional Applications

Inorganic Chemistry

• Focuses on substances that generally do not contain carbon.

• Job possibilities and specific companies in this field include:

  • Environmental Science: Environmental Protection Agency (EPA), Bechtel, Energy Solutions, and Tetra Tech.

  • Fibers and Plastics: Albermarle, Bayer, Dow Chemical Company, and Dupont.

  • Microchips: Intel, IBM, Texas Instruments, and Samsung Semiconductor.

  • Mining, Ore, and Metals: Vale, Rio Tinto, Shenhua Group, and Barrick.

  • Paint, Pigment, and Coatings: Continental Chemical, Valspar, Glidden Paints, and Shepherd Chemical Company.

Organic Chemistry

• Focuses on carbon-containing compounds.

• Career opportunities include:

  • Organic Chemistry Professor

  • Food Scientist

  • Forensic Analyst

  • Environmental Scientist

  • Materials Scientist

  • Analytical Chemist

  • Pharmacologist

Physical Chemistry

• Deals with the principles of physics involved in chemical interactions.

• Covers the physical properties of chemical compounds using laws and concepts of Physics such as motion, energy, force, time, statistical mechanics, quantum chemistry, and thermodynamics.

• Primary areas of examination include:

  • The behavior of matter on a molecular and atomic level.

  • The mechanisms of how chemical reactions occur.

• Physical chemists focus on understanding the physical properties of atoms and molecules and what these properties reveal, using theories of physics and mathematical computations.

Analytical Chemistry

• Involves the use of knowledge regarding chemistry, instrumentation, computers, and statistics to solve problems across all industrial areas.

• Opportunities include:

  • Quality assurance specialists: Ensure laboratories follow documented and approved procedures.

  • Quality control experts: Ensure the quality of products produced by laboratories.

  • Developing and using complex analytical techniques.

  • Government agency work verifying compliance with regulatory requirements.

  • Entrepreneurial opportunities specializing in specific analyses or classes of compounds.

Biochemistry

• Investigates chemical interactions and reactions within living organisms; a fusion of biology and chemistry.

• Job possibilities include:

  • Forensic science technician or Forensic scientist.

  • Microbiologist, Biochemist, or Biologist.

  • Research scientist or Biochemistry professor.

  • Chemical engineer.

Theoretical Chemistry

• Involves investigating theoretical methods that can predict the outcomes of chemical experiments.

• Specific listed roles include:

  • Quantum - AI Researcher

  • Scientific Researcher

  • R&D Inhalation chemist

  • Lab Analyst

  • Exoplanet Experimental Studies

Detailed Biochemistry: Metabolic Cycles and Pathways

• The Citric Acid Cycle (also known as the Krebs cycle or TCA cycle) involves the interaction of various acids and cofactors:

  • Components include: Citric Acid, cis-Aconitic Acid, Isocitric Acid, $\alpha$-Ketoglutaric Acid, Succinic Acid, Fumaric Acid, Malic Acid, and Oxaloacetic Acid.

  • Key cofactors and enzymes mentioned include: $Fe$, $GSH$, $B2$, $Mg$, $Mn$, $B1$, $B3$, and $B11$.

• The Urea Cycle occurs within the cytosol and the mitochondrial matrix:

  • Includes: Ornithine, Citrulline, Argininosuccinate, Arginine, and Urea.

  • Steps involve enzymes such as Argininosuccinate synthetase and Arginase.

  • Reactants and products include: $ATP$, $AMP$, $PP$, $H_2O$, $HCO_3^-$, and $NH_4^+$.

• Electron Transport Chain (ETC) involves:

  • Complexes I, II, III, and IV, and ATP Synthase.

  • Molecules such as Coenzyme Q10 ($CoQ$), $NADH$, and $FADH_2$.

• Other metabolic processes include:

  • $\beta$-Oxidation of Fatty Acids.

  • Ketogenesis (generating B-OH-Butyric Acid).

  • Metabolism of Carbohydrates, Proteins, and Amino Acids.

Chemistry in Everyday Life

• Examples of chemical processes or substances encountered daily include:

  1. Discoloration of leaves.

  2. Food Digestion.

  3. Common salt (Sodium Chloride).

  4. Ice floating on water (due to density properties).

  5. Tears produced while chopping onions.

  6. The function of Sunscreen.

  7. Medicines and hygiene products.

  8. Baking Soda.

  9. Food Preservatives.

  10. Biological basis of Emotions.

  11. Coffee.

Types of Research in Chemistry

1. Basic Research: Carried out primarily for the purpose of gaining new knowledge.

2. Applied Research: Carried out specifically to solve a practical problem.

3. Technological Development: Involves the production and use of products to improve the quality of life (e.g., developing a new refrigerant or redesigning computer chips).

Matter and Its Properties

Definitions

• Matter: Anything that has mass and takes up space (volume).

• Mass: The measure of the amount of matter present in an object.

Building Blocks

• Atoms: The smallest unit of an element that maintains the properties and identity of that substance.

• Element: A pure substance that cannot be broken down into simpler, stable substances, made of only one type of atom.

• Compound: A substance that can be broken down into simple stable substances. Each compound is comprised of atoms of two or more elements that are chemically bonded.

Categories of Properties

• Extensive Properties: Depend on the amount of matter present. Examples include Volume, Mass, and the amount of energy in a substance.

• Intensive Properties: Do not depend on the amount of matter present. Examples include Melting point, Boiling point, Density, Ability to conduct electricity, and Ability to transfer energy as heat.

• Physical Properties: Characteristics that can be observed or measured without changing the identity of the substance, such as color, density, melting point, and boiling point.

Physical and Chemical Changes

Physical Changes

• A change in a substance that does not change its identity.

• Examples: Melting wax, dissolving sugar in coffee, steam condensing into liquid water, grinding, cutting, shredding, and folding.

• Changes in State: A specific type of physical change involving the transition from one state of matter to another.

  • Solid: Definite volume and definite shape. Particles are packed in fixed positions and held by strong attractive forces.

  • Liquid: Definite volume but indefinite shape. Particles are close but can move past one another because they move rapidly enough to overcome some attractive forces.

  • Gas: No definite volume or shape. Particles move very rapidly and stay at great distances from each other; attractive forces have little effect.

  • Plasma: A high-temperature physical state where atoms lose most of their electrons. It is essentially an electrically charged gas.

Chemical Properties and Changes

• Chemical Property: A substance’s ability (or inability) to undergo changes that transform it into different substances. Examples include flammability, toxicity, acidity, and reactivity.

• Chemical Change (Reaction): A change where one or more substances are converted into different substances.

  • Reactants: Substances that react in the change.

  • Products: Substances formed by the change.

  • Example (Burning Charcoal): $Carbon + Oxygen \rightarrow Carbon\,Dioxide + Ash$.

  • Example (Alka-Seltzer): Citric acid and sodium bicarbonate react in water to produce carbon dioxide gas.

Classification of Matter

• All matter is categorized as either a pure substance or a mixture.

Mixtures

• A blend of two or more kinds of matter, each retaining its own identity and properties.

• Components are mixed physically and can usually be separated.

• Homogeneous Mixtures (Solutions): Uniform in composition (e.g., air, sugar in water, steel).

• Heterogeneous Mixtures: Not uniform in composition (e.g., sand, chicken noodle soup, wood, granite, blood, smoothies, suspensions, colloids).

Pure Substances

• Have a fixed composition and are always homogeneous.

• Every sample has exactly the same characteristic physical and chemical properties.

• Every sample has exactly the same composition. For example, pure water is always $11.2\%$ hydrogen and $88.8\%$ oxygen by mass.

• Pure substances are either Elements or Compounds.

Questions & Discussion

• What two properties must matter have? Mass and Volume.

• What is an example of a homogeneous mixture? Air, sugar in water, and steel.

• What is an example of a heterogeneous mixture? Sand, chicken noodle soup, wood, granite, blood, and smoothies.

• What is an example of an element? Any of the 118 identified elements on the periodic table.

• What is an example of a compound? Water, sodium chloride (salt), and sucrose (sugar).

• What terms indicate a physical change? Melting, boiling, and dissolving.

• What terms indicate a chemical change? Burning, cooking, rusting, rotting, and bleaching.

• Identify the research type for the following scenarios:

  • A new refrigerant that is less damaging to the environment is developed: Applied Research.

  • A new element is synthesized in a particle accelerator: Basic Research.

  • A computer chip is redesigned to increase the speed of the computer: Technological Development.