Unit 1 Introduction

Unit 1 Introduction - What Am I Doing Here? What is...

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Unformatted text preview: What Am I Doing Here? What is chemistry? Chemistry: the study of all substances and the changes they undergo. Touches nearly all aspects of our lives… can you think of some examples? The central science: it overlaps with so many other sciences. WHY STUDY CHEMISTRY? It will help you understand the world! HINT: Don’t try to memorize! The task is easier if you concentrate on understanding concepts, not memorizing facts. Biochemistry (my favorite) • Study of chemical reactions that occur in living organisms What it studies: DNA to RNA to Proteins CSI­­Forensics Springer­­paternity tests (can disprove a parent with blood types, but you cannot prove without DNA Genetically altered plants/animals "Alba", the green fluorescent bunny, is an albino rabbit. This means that, since she has no skin pigment, under ordinary environmental conditions she is completely white with pink eyes. Alba is not green all the time. She only glows when illuminated with the correct light. When (and only when) illuminated with blue light (maximum excitation at 488 nm), she glows with a bright green light (maximum emission at 509 nm). She was created with EGFP, an enhanced version (i.e., a synthetic mutation) of the original wild­ type green fluorescent gene found in the jellyfish Aequorea Victoria. EGFP gives about two orders of magnitude greater fluorescence in mammalian cells (including human cells) than the original jellyfish gene. Alba, the fluorescent bunny. Organic Chemistry Study of substances containing carbon What you can do with organic chemistry: (closely related to biochemistry­­they can overlap in many areas) Discovery of new drugs Reactions mechanisms: how drugs work in the body Drug interactions: how drugs (prescription and illegal) interact with each other and herbal remedies/medications Peanut allergies (protein is the cause) 100 people a year killed by peanut allergy Inorganic Chemistry: • • Study of all substances other than those containing carbon What we will study: • • • Naming (what they are called) Structure (what they look like) Function (how they work together­­valence electrons) Physical Chemistry: Study of structures of substance, how fast they change, and the role of heat in chemical changes We study: Real life example: THE LIGHTSTICK Thermochemistry: heat flowing in/out of a chemical reaction Exothermic/Endothermic reactions The chemistry behind heat and light Howstuffworks.com Analytical Chemistry: (a lot of math here) Study of what is in a substance and how much is there Techniques used: Liquid/gas chromatography NMR­­nuclear magnetic resonance Spectrophotometry NMR machice (one type): used to find structures of molecules as well as many other uses Chromatography: used to separate/purify substances as well as identify them Spectrophotometer: measures light intensity Scientific Method What is the scientific method? You use it every day without knowing it. Example: Why do we need a scientific method? Weather ­­if it is cloudy you predict it may rain and dress accordingly Flashlight It allows a standard for experimentation. Gives scientist rules to follow so tests can be repeated Steps of the scientific method: Observation: ask a question after researching the topic) Hypothesis: predict an answer (educated guess Experiment: test your hypothesis; designed to be repeatable Data analysis: study the results Conclusion: come up with an answer, either proving or disproving your hypothesis (it is okay to have an incorrect hypothesis; if you always know the answer ahead of time there is no need to do the experiment) Theory vs Law Scientific theory: a well­tested explanation for a broad set of observations (it may be changed after future tests) Scientific law: a concise statement that summarizes the results of many observations and experiments (not an explanation) 5 branches of Chemistry 1. 2. 3. 4. 5. Biochemistry: Study of chemical reactions that occur in living organisms Organic Chemistry: Study of substances containing carbon Inorganic Chemistry: Study of all substances other than those containing carbon Physical Chemistry: Study of structures of substance, how fast they change, and the role of heat in chemical changes Analytical Chemistry: Study of what is in a substance and how much is there Unit 1: Introduction, Scientific Method, Safety, Matter, & Energy Ch. 1.1 – 1.3 & 2.1 – 2.4. Matter Matter: Has mass and volume. Law of Conservation of Matter: Matter is neither created nor destroyed. Examples of Matter? States of Matter State Example Shape vs. Volume Solid Liquid Gas Plasma Physical vs Chemical Properties: Physical: a quality that can be observed or measured without changing the substance’s composition Chemical: a quality that can only be observed by changing the composition. Physical vs Chemical Changes: “Has the change altered the identity of the substance”. Physical: Does not alter the substance’s identity. Chemical: Mass change, forms a precipitate, releases heat and / or light, color changes, gives off gas. 5 Indicators of a Chemical Reaction 1. 2. 3. 4. 5. Formation of a precipitate (ppt) Evolution of a gas Color change Release/absorption of heat or light Apparent change in mass (it looks like the mass is smaller/larger) Classification of Matter (with examples) Homogeneous: Element: Can not be separated into simpler substances by a chemical change. Compound: Combined by chemical reaction in a fixed proportion. Use symbols Periodic table (properties) Organic Inorganic Solutions: Heterogeneous: Visibly different parts. Mixture: ADDITIONAL INFORMATION: • Physical properties can be observed using any of the 5 senses. Separation Techniques for Mixtures Terms to know (they will appear throughout the course) Filtration Distillation Malleable: able to be shaped or bent Ductile: able to be pulled into wire Energy Energy: The capacity to do work or to produce heat. Work: the capacity to move an object over a distance against a resisting force. Where is energy found: Train, sunlight, chocolate bar, etc Radiant energy: Kinetic energy: energy of motion. KE = 1/2mv2 Mechanical energy: carried by moving parts of a machine Thermal energy: caused by random internal motion of particles of matter Potential energy: Energy possessed by objects because of their position. Gravitational Potential Energy GPE = mgh = mass x acceleration due to gravity x height Electrical Potential Energy: exists when objects with different electrical charges are separated Chemical Potential Energy: exists due to arrangement of particles that make up a substance Law of Conservation of Energy: In any process, energy is neither created nor destroyed. Measuring Energy Calorie (cal): a common unit of energy. One calorie = the amount of heat needed to raise the temp of one gram of water by one Celsius degree. Joule: The SI unit of energy. 1 cal = 4.184 J ...
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