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Kinetics

  1. what is enthalpy?
    • also called delta H value
    • difference between potential energy of products and potential energy or reactants
  2. endothermic
    • absorbs energy
    • positive delta H
    • products have more energy than reactants
  3. exothermic
    • releases energy
    • negative delta H
    • products have less energy than reactants
  4. what is the function of a catalyst?
    • creates an alternate reaction pathway
    • lowers first activation energy
    • does not affect delta H value
    • not used up or changed during a reaction
  5. reversible reactions
    reactants are "re formed" from products
  6. non reversible reactions
    occur when a solid precipitate occurs or a gas is produced and escapes
  7. what are 2 characteristics of an effective collision? (collision theory)
    • proper orientation
    • amount of energy
  8. name some factors that affect reaction rate:
    • 1) nature of reactants (# of bonds, is it (aq))
    • 2) concentration of reactants
    • 3) temperature
    • 4) surface area
    • 5) pressure (gases)
  9. In order for a chemical reaction to occur, there must always be
    an effective collision between reacting particles
  10. Which conditions will increase the rate of a chemical reaction?
    increased temperature & increased concentration of reactants
  11. what is entropy?
    • disorder/randomness
    • more disorder = more entropy
    • nature tends towards higher entropy
    • delta S value
  12. what might lead to higher entropy?
    • 1) phase (s to l to aq to g)
    • 2) more moles of products than reactants
    • 3) products simpler than reactants
    • 4) higher temperature = more entropy
  13. free energy (delta G) equation
    (Delta H) - (Temperature in K)(Delta S)
  14. a reaction is always spontaneous if (-)...
    • delta H is negative (exothermic)
    • delta S is positive (more entropy)
  15. a reaction is never spontaneous if (+)...
    • delta H is positive (endothermic)
    • delta S is negative (losing entropy)
  16. a reaction is spontaneous at high temperatures if (-)...
    • delta H is positive (endothermic)
    • delta S is positive (more entropy)
  17. a reaction is spontaneous at low temperatures if (+)..
    • delta H is negative (exothermic)
    • delta S is negative (losing entropy)
Author
katw3
ID
338600
Card Set
Kinetics
Description
kinetics unit for NYS regents review 2018
Updated

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