Chapter 18

Card Set Information

Chapter 18
2011-08-10 19:40:11

Gen Chem II
Show Answers:

  1. Arrhenius Acid
    a substance that yields hydrogen ions (H+) when dissolved in water
  2. Arrhenius Base
    a substance that yields hydroxide ions (OH-) when dissolved in water
  3. Bronsted-Lowry Acid
    a proton (H+ ion) donor
  4. Bronsted-Lowry Base
    a proton acceptor
  5. reaction order
    the power to which a concentration of a reactant is raised in a rate law
  6. osmosis
    the net movement of solvent through a semi-permeable membrane toward the solution with greater concentration
  7. Henry's Law
    a law stating that the concentration of a gas in a solution is proportional to the pressure of that gas over the solution
  8. catalyst
    a substance that increases the speed of a chemical reaction without itself undergoing a permanent change
  9. reaction mechanism
    a detailed picture or model of how a chemical reaction occured
  10. intermediate
    a substance formed in one elementary step and consumed in a later elementary step
  11. molecularity
    the number of particles that participate as reactants in an elementary step
  12. miscible
    liquids that mix in all proportions
  13. activity
    the ratio of a concentration or pressure to a standard concentration or pressure
  14. in any Bronsted-Lowry reaction, an acid _______ a proton (and therefore becomes a base), and a base ______ that proton (and becomes an acid)
    an acid DONATES a proton and then becomes a base while a base ACCEPTS a proton and then becomes an acid; such a pair of species is called a conjugate acid-base pair
  15. amphoteric
    a substance that has the ability to sometimes act as an acid and to sometimes act as a base; ex. water
  16. autoionization of water
    • even in pure water some water molecules will act as acids and donate protons to other water molecules that are acting as bases
    • H2O(l) + H2O(l) <---> H3O+(aq) + OH-(aq)
    • it gets its own eq. constant (at room temperature), kw=1.00 x 10-14
  17. the autoionization of water is: ___________
    endothermic; as temperature increases, so does kw
  18. kw=[H3O+][OH-]
    if you know the concentration of one, you can calculate the concentration of another (at room temperature)
  19. pH = - log [H+]
    [H] is a unitless activity
  20. mantissa
    the portion to the right of the decimal points; in a logarithm only the digits to the right are significant
  21. pkw = pH + pOH
    • p______ = -log________
    • @ room temperature pH + pOH = 14
  22. a _________ in pH by 1 unit corresponds to an ________ in H+ by a factor of 10
    a DEcrease in pH by 1 unit corresponds to an INcrease in H+ by a factor of 10
  23. acids and bases are electrolytes; they ionize in solution
    a greater acidity is not due to acid concentration, instead it is due to a more COMPLETE ionization
  24. strong acids and strong bases undergo ________ ionization
    COMPLETE ionization; an acid/base that doesn't ionize to completion is WEAk
  25. there are SIX strong acids (that are stable and common):
    • HCl
    • HBr
    • HI (!)
    • H2SO4
    • HNO3 (nitrate)
    • HClO4
    • Chemistry Brings Infinite Sorrow. Not Cool.
  26. strong bases:
    the two left-most columns of the periodic table (EXCEPT BERYLLIUM) paired with OH- are strong bases (not all are super soluble)
  27. the stronger the acid of a pair, the weaker the base of the pair:
    the stronger the base of a pair, the weaker the acid
  28. polyprotic acid
    an acid that's capable of donating more than one proton to a base; the donation of each proton becomes progressively less likely, therefore each constant (ka) has a different value
  29. the percent ionization is ________ for more dilute solutions
    the percent ionization is GREATER for more dilute solutions
  30. Ka x Kb = Kw
    • bleh. same for log form.
    • Kw at room temp (25 deg C) = 1.00 x 10-14
  31. if you're given a compounds that has N in it, chances are it's a:
  32. when you're finding the pOH or pH of something, don't forget to multiply the concentration of said base or acid by its:
    CONCENTRATION!!!! Why wouldn't you?
  33. if you're finding a strong base/acid and you need to write out the equation or even the equilibrium ratio or whatever you dON'T have to take into account water because:
    it's STRONG, so it dissociates on its own, it doesn't need water; if it's WEAK you add water because you can assume that not all of it will dissociate into ions
  34. think about this:
    when you add another gas but keep the total pressure the SAME, think about the gasses already present in the reaction have to DECREASE their partial pressures to compensate for you adding that other gas; (ex: if both have a p.pressure of .5 but then you add and extraneous gas that has a p.pressure of .2 and the total pressure STAYS at 1 atm, the two gasses that started out in the system must DECREASE in pp to compensate for the addition of a new gas!)
  35. `when you have NO volume change, adding inert gas doesn't change:
    moles OR pressure of a gas being used in a reaction
  36. leveling effect
    water makes all strong acids appear to be equivalent in their extent of ionization (ie 100%); using a solvent that's less acetic than water (such as ammonia) will remove the leveling effect for strong bases