CHEM 101 1st Edition Lecture 1 Outline of Current Lecture I. Basic Concepts of ChemistryII. States of MatterIII. Levels of MatterIV. Classifying MatterV. Physical and Chemical PropertiesCurrent Lecture- Global Warming is a Theory (Hypothesis)- which are proven by data. Data can beo Qualitative Informative- something you can observe No numbers involved Color, appearance, “large/small” Stating that something is hot/cold (not specific degree temperature) Identifying something by smello Quantitative Informative- something you can measure Numerical data (measured) Dimensions given Ex: wavelength of color, specifying specific degree temperature)- Series of reproducible experiments (may) result in law or general rule- Theory- a well tested unifying principle that explains a lawo Can suggest new hypothesizes that can be tested experimentally- States of Mattero Solids- rigid shape, fixed volume External shape may reflect the atomic and molecular arrangements Structure reasonably well understoodo Liquids- no fixed shape Don’t expand to fill a container completely Structure isn’t well understoodo Gases- no fixed shape, expands Well defined theoretical understanding- Levels of Mattero Macroscopic Level- hundreds of cmo (Sub)Microscopic/Particulate Level- 10^(-12) cmThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.100’s cm…………………………….. 10^(-12) cmo Chemical Symbols allows for us to connect observations with imagination Observation- what we can see (microscopic level) Imagine- what we cannot see (particulate level) Symbols- represent what we understand- Classifying Mattero Mixtures- have more than one substance present Homogeneous Mixture- two or more substances in the same phase; uniform composition; components aren’t visually distinguishable (salt water) Heterogeneous Mixture- no uniform composition; components are often visually distinguishable (milk, muddy water, sand and water)- You can separate heterogeneous mixtures with a filter (coffee filter)o Pure Substances- have well defined physical and chemical properties; can be classified as: Elements- consist of only one sort of atoms; cannot be further simplified by ordinary means- Recorded in Periodic Table of Elements- Currently 118 recorded- Mercury is the only liquid at room temperature Compounds- can be further reduced into tow or more elements- Reaction of two elements to a compound (NaCl= Na+Cl)- All compounds consist of molecules or ionso Molecule- use a “molecular formula”o Ionic Compound- described by a “formula unit”- Physical Propertieso Color, state of matter, melting point, density, solubility, viscosity, etc.Microscopic Level (Sub)Microscopic or Particulate LevelHomogeneous MixtureHeterogeneous MixtureElementsCompounds Matter Anything that takes space and has mass MixturesMore than one substance present Pure Substances Fixed composition; can’t be further purifiedMacroscopic Levelo Extensive Properties- depends on the amount of the substance (mass, volume)o Intensive Properties- don’t depend on the amount of the substance (density, melting point)- Chemical Propertieso Chemical Property- indicates whether (and sometimes how readily) a material undergoes a chemical change with another material. Ex: Chemical property of Hydrogen gas is that it reacts vigorously with oxygen gaso Chemical Changeo Indicate if each example is a physical or chemical property Color is red- physical intensive property Iron turns to rust- chemical property Hydrogen explodes when ignited in air- chemical property Density of titanium is 4.5 g/cm^3- physical intensive property Tin melts- physical intensive property Plant pigment is green- physical intensive
View Full Document
Unlocking...