Chemistry ch 3

  1. heterogeneous
    contain more than one visible phase and are not uniform throughout
  2. homogeneous
    also contain more than one kind of material and can be separated easily
  3. mixtures (solutions)
    materials are so evenly distributed that the appear to be one phase
  4. pure substances
    always have the same somposition
  5. 2 types of pure substances
    • elements
    • compounds
  6. elements
    contain only one kind of atom
  7. compounds
    contain more than one kind of atom
  8. phase
    part of a material that has a uniform set of properties
  9. interface
    area where two phases meet
  10. physical properties
    • can be observed or measured
    • length
    • mass
    • shape
    • color
    • texture
    • MP
    • BP
    • ductility
    • density
    • malleability
    • solubility
    • volume
  11. physical change
    the identity of the substance is not changed after the conditions change
  12. distillation
    difference in boiling point
  13. chemical property
    explains how it reacts with another substance
  14. Chemical change
    • New substance is formed with new properties after conditions change
    • color change
    • gas given off
    • change in temp
    • precipitate forms
  15. Endothermic
    energy absorbed, and the have a higher energy (cold)
  16. exothermic
    energy released, and the products have less energy (hot)
  17. activitaion energy
    energy required to start the reaction
  18. What do you need to raise the temperature of water 1 degree?
    4.184 j
  19. 1 calorie =
    4.184 joules
  20. 1 kilocalorie (C) =
    1,000 calories (c)
  21. specific heat
    the amount of heat needed to raise the temperature of one gram of a substance
  22. heat gained formula
    q=m x T x Cp
  23. When the system loses heat, use
  24. When a substance gains heat, use
Card Set
Chemistry ch 3