Chemistry Final

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Chemistry Final
2013-01-12 20:19:37

Semester 1
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  1. Scientific Method (3 steps)
    • 1. Making observations
    • 2. Testing hypotheses
    • 3. Developing theories
  2. Theory
    a well-tested explanation for a broad set of observations
  3. Experiment
    a repeatable procedure that is used to test a hypothesis
  4. Hypothesis
    a proposed explanation for an observation
  5. Observation
    information obtained through the senses; observation in science often involve a measurment
  6. A scientific law
    A concise statement that summarizes the results of many observations and experiments
  7. Inferences
    To draw a conclusion based on what one already knows
  8. Three states of matter
    • Solid
    • Liquid
    • Gas
  9. Solid:
    What type of matter? Particles?
    • Form of matter that has a definite shape and volume.
    • Particles are packed tightly together, orderly arrangement.
  10. Liquid:
    What type of matter? Particles?
    • Form of matter that has an indefinite shape, flows, yet has a fixed volume.
    • Particles are free to flow.
  11. Gas:
    What type of matter? Particles?
    • Form of matter that takes both the shape and volume of the container.
    • Particles move fast and are much farther apart.
  12. Chemical vs. Physical changes
    • Chemical: change that produces matter with a different composition than the original matter
    • Physical: change during which some properties change but the composition stays the same
  13. Compounds vs. Elements (which breaks down?)
    Compounds can be broken down into simpler substances by chemical means, but elements cannot.
  14. Compound
    a substance that contains two or more elements chemically combined
  15. Element
    the simplest form of matter that has a unique set of properties; can't be broken down into simpler substances by chemical means
  16. Chemical property
    the ability of a substance to undergo a specific chemical change
  17. Physical property
    a quality or condition of a substance that can be observed or measured without changing the composition
  18. Chemical symbol
    a one or two letter representation of an element
  19. Heterogeneous mixture
    mixture that is not uniform in composition; components aren't evenly distributed throughout the mixture
  20. Homogeneous mixture
    mixture that is uniform in composition; evenly distributed and not easily distinguished
  21. Substance (AKA pure substance)
    matter that has a uniform and definite composition
  22. Solution (homogeneous or heterogeneous?)
    a homogeneous mixture; consists of solutes dissolved in a solvent
  23. Solute
    dissolved particles in a solution
  24. Solvent
    dissolving medium in a solution
  25. Law of conservation of mass
    mass can be neither created nor destroyed
  26. Absolute zero
    the zero point on the Kelvin temperature scale; -273.15 degrees C
  27. Accepted value
    a quantity used by general agreement of the scientific community
  28. Accuracy
    the closeness of a measurement to the true value of what is being measured
  29. Precision
    describes the closeness of a set of measurements taken under the same condition
  30. Density (and equation)
    • ratio of the mass of an object to its volume
    • D=m/v
  31. Experimental value
    a quantitative value measured during an experiment
  32. Significant figures
    all the digits that can be known precisely in a measurement, plus a last estimated digit
  33. Percent error equation
    Percent Error= error/accepted value  x 100%
  34. Basic units of length (x3)
    • centimeter (cm)
    • meter (m)
    • kilometer (km)
  35. Basic units of volume (x4)
    • liter (L)
    • milliliter (mL)
    • cubic centimeter (cm3)
    • microliter
  36. Basic units of mass (x4)
    • kilogram (kg)
    • gram (g)
    • milligram (mg)
    • microgram
  37. Basic units of temperature (x2)
    And equations for both
    • Kelvin scale
    • Celsius scale
    • K=C+273
    • C=K-273
  38. Qualitative
    used to describe what the object is like; cannot be definitively measured
  39. Quantitative
    something that can be counted or measured
  40. Anion
    any atom or group of atoms with a negative charge
  41. Cation
    any atom or group of atoms with a positive charge
  42. Binary compound
    • a compound composed of two elements
    • examples: NaCl and Al2O3 
  43. Ionic compound
    a compound composed of positive and negative ions
  44. Molecular compound
    a compound composed of molecules
  45. Formula unit
    the lowest whole-number ration of ions in an ionic compound
  46. Molecule
    a neutral group of atoms joined together by covalent bonds
  47. Ion
    An atom or group of atoms that has a positive or negative charge
  48. Monatomic ion
    a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons
  49. Polyatomic ion
    a tightly bound group of atoms that behaves as a unit and has a positive or negative charge
  50. Ternary compound
    a compound containing three different elements
  51. Skeleton equation
    a chemical equation that doesn't indicate the relative amounts of reactants and products
  52. Balanced equation
    a chemical equation in which mass is conserved; each side of the equation has the same number of atoms of each element
  53. Catalyst
    • substance that increases the rate of reaction
    • not used up in the reaction
  54. Coeffecient
    a small whole number that appears in front of a formula in a balanced equation
  55. Combination reaction (AKA synthesis reaction)
    a chemical change in which two or more substances react to form a single new substance
  56. Combustion reaction
    a chemical change in which an element or a compound reacts with oxygen; often produces energy in the form of light and heat
  57. Decomposition reaction
    a chemical change in which a single compound is broken down into two or more simpler products
  58. Single replacement reaction (AKA displacement reaction)
    a chemical change in which one element replaces a second element in a compound
  59. Double replacement reaction
    a chemical change that involves an exchange of positive ions between two compounds
  60. Net ionic equation
    an equation for a reaction in solution showing only those particles that are directly involved in the chemical change
  61. Spectator ion
    an ion that isn't directly involved in a chemical reaction
  62. Subscript
    number that is written below the element that lets you know how many molecules of that element are present
  63. Mole
    the amount of a substance that contains 6.02 x 1023 representative particles of the substance
  64. Avogardo's number
    6.02 X 1023
  65. Molar mass
    mass of a mole of any substance
  66. Percent composition
    the percent by mass of each element in a compound
  67. Empirical formula
    a formula with the lowest whole-number ratio of elements in a compound
  68. Molecular formula
    a chemical formula of a molecular compound that shows the kinds and numbers of atoms present in a molecule of a compound
  69. Standard temperature and pressure (STP)
    the conditions under which the volume of a gas is usually measured