Chem ch. 1

  1. Pure Sciences
    • Promote understanding of how the univerese and its parts function
    • IE: astronomy; biology; chemistry; physics
  2. Applied Sciences
    • Makes uses of the results of pure sciences
    • IE: agriculture; engineering; medicine
  3. Chemistry
    • Study of non-living material
    • -composition materials and changes materials undergo
    • -energy changes that accompany chemical changes
    • -discover and develop new material from existing ones
  4. Scientific Method
    series of activities involving observations and experimentation and culminating of theories to explain and predict natural phenomena
  5. Steps of Scientific Method
    • Observations (what you see / collection of data)
    • Question and hypothesis (hypothesis: tentative answer to the question / explanation for the properties or behavior of matter that accounts for a set of observations must be testable)
    • Experimentation: (Date, Title, aim/purpose, list of equipment, procedure, data analysis, and conclusion)
  6. Scientific Law
    Describes how nature operates under a specific set of conditions
  7. Theories
    Explains why observations, hypotheses, or laws apply under many different circumstances
  8. Independent Variable
    factor varied by you
  9. dependent variable
    factor that will change as a result of a change in the independent variable
  10. control experiment
    • serves as a standard for comparison
    • exposed to smae conditions as teh experiment except for the variables to be tested
  11. constants
    all the factors that the experimenter attempts to keep unchanged in the course of the experiment
  12. trials
    replicate groups subjected to the same conditions in an experiment
  13. Matter
    anything that occupies space nad has mass
  14. Non-matter
    • does not occupy space / have a mass
    • eg: sunlight/heat
  15. Classification of matter
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  16. Element
    • pure substances that contains atoms of one type
    • cannot be broken down into simpler substances even by a chemical reaction
  17. compounds
    substance composed of 2 or more elements combined in defined portions IE: water
  18. Metals
    • 90 of the 144 elements / appear on L side of periodic table
    • properties:
    • -solid at room temp (except mercury)
    • -good conductor of heat/electricity
    • -lustrous on fresh surfaces
    • -malleable & ductile
  19. Nonmetals
    • 17 elements / Appear on the R side of periodic table
    • Room temp: 11 gases / 5 solid / 1 liquid
    • poor conductors of heat & electricity
  20. Metalloids
    Seven elements are metalloids. Their properties are between those of metals and nonmetals. Metalloids are semiconductors and are important to the electronics industry. (a) Boron and (b) silicon are examples of metalloids
  21. Mixture
    • 2 or more substances that are physically mixed, not chemically combined
    • 2 or more substances in different proportions
    • substances that can be serperated by physical methods
  22. homogeneous mixture
    • composition is uniform throughout
    • different parts in mixture are not visible
  23. heterogeneous mixture
    • composition of substances is not uniform
    • composition varies from one part of the mixture to another
    • different parts of mixture are vissible
  24. Standard methods of serpartion used in chemistry
    • filtration
    • evaporation to dryness
    • simple distillation
    • fractional distillation
    • magnetism
    • precipitation
  25. Ordinary methods of seperation
    • decantatin
    • winnowing
    • handpicking
  26. States of matter
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  27. Solid (s)
    • fixed shape that is not related to the shape of the container holding it
    • low compressibility (particles are tightly packed)
  28. Liquid (l)
    • no fixed shape
    • fills only the portion of container it occupies
    • can be slighlty compressed ( particles have little free space)
  29. Gas (g)
    • no fixed shape
    • expands to fill its entire container
    • changes volume when compressed
  30. aqueous (aq)
    dissoled in water
  31. Physical properties of matter
    • measured withoug changing substance
    • physical state / color / odor / density / boiling point
  32. Chemical properties of matter
    • describes substance's reactivity
    • flammability / corrosiveness
  33. Extensive properties of matter
    • depends on the amount of matter present
    • mass / volume
  34. intensive properties of matter
    • does not depend on the amount of matter present
    • density / color / temperature
  35. Density
  36. Temperature
    • TK=TC +273.15
    • TF = 1.8(TC)+32
  37. Chemical change (reaction)
    • process in which one or more substances are converted into one or more new substances
    • bubbling / permanent color change / sudden change in temperature
  38. Physical change
    process that changes the physical properties of a substance without changing its chemical composition
  39. change of state
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  40. Scientific notation
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  41. Precision
    • the extent of the agreement between repeated measurements of its value.
    • If repeated measurements are close in value, then the number is precise, but not necessarily accurate
  42. Accuracy
    • the difference between the value of a measured number and its expected or correct value.
    • The number is accurate if it is close to its true value (much like hitting a bulls-eye on a dart board).
  43. multiplicaiton & division of significant figures
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  44. Addition and subtracion of significant figures
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  45. units
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  46. Unit analysis
    • A possible approach to problem solving involves 4 steps:
    • 1 .Decide what the problem is asking for.
    • 2.Decide what relationships exist between the information given in the problem and the desired quantity.
    • 3.Set up the problem logically, using the relationships decided upon in step 2.
    • 4.Check the answer to make sure it makes sense, both in magnitude and units.
  47. Energy
    capacity to do work or transfer heat
  48. Kinetic energy
    the energy due to motion
  49. potential energy
    energy possessed by an object becasue of its position
  50. Units for energy
    • 4.184J = 1 cal
    • calorie is the amount of energy required to raise 1g of water by 1o C
    • 1 Cal = 1000 cal
  51. Exothermic
    process that releases heat energy
  52. Endothermic
    process that absorbs energy
  53. Heat
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  54. Specific heat capacity
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Card Set
Chem ch. 1
Matter & Energy