MCAT CHEM 3

  1. colligative property?
    property derived solely from the number of particles present, not the nature of those particles
  2. name 4 colligative property
    freezing point depression, boiling point elevation, osmotic pressure, vapor pressure lowering
  3. formula for freezing point depression? for boiling point elevation?
    • freezing point- delta Tf=Kfm
    • boiling point - delta Tb=Kbm

    K= molality of solution
  4. formula for osmotic pressure
    • P=MRT
    • M- molarity
    • R-gas constant
  5. solubility?
    measure of the amount of substance that can be dissolved in a particular solvent at a particular temp
  6. electrolyte?
    solute whose solution is conductive
  7. formula for percent composition by mass
    mass of solute/mass of solution x 100%
  8. definition of normality
    The normality of a solution is the number of gram equivalent weight of a solute per liter of its solution
  9. gram equivalent weight
    equivalent weight of a compound can be calculated by dividing the molecular weight by the number of positive or negative electrical charges that result from the dissolution of the compound.
  10. Fe(OH)3 <---->Fe3+ (aq) +3 OH- (aq)
    1.what's ion product (IP)
    2.whats solubility product constant (Ksp)
    3.difference btwn IP and Ksp?
    • 1.IP=[Fe3+][OH-]3
    • 2.Ksp=[Fe3+]sat[OH-]3sat
    • 3.IP is with respect to initial concentrations. Kspis with respect to concentration of a saturated solution at equilibrium
  11. common ion effect?
    slightly soluble salt is added to a solution which already contains one of its components, the added salt is less soluble than if it were added to a pure solvent.
  12. difference btwn Brownsted Lowry and Lewis definition of acids
    Brownsted Lowry acid- proton donar

    Lewis acid- electron acceptors
  13. at 25o, pH +pOH=?
    14
  14. water dissociation constant (Kw) at 25oC
    • Kw=[H+][OH-]=1 x10-14
    • also
    • Kw=Ka x Kb
  15. would pH of 1.4x10-4M HCl solution be greater or less than 4
    less
  16. HCO3-(aq) <----> H+(aq)+CO3-2
    what is Ka for HCO3?
    what is Kb for CO3
    • Ka=[H][CO3]/[HCO3]
    • Kb=[H][CO3]/[CO3]
  17. (t/f) an acid equivalent is equal to one mole of H+
    True
  18. (t/f) a buffer solution consists of a mixture of strong acid and its salt
    false, it consists of mixture of weak acid and weak base with their salts
  19. a reducing agent
    a specie that loses electrons that causes another specie to be reduced (gain the electrons)
  20. whats oxidation number of a group VIIA elements in a compound?
    • -1,
    • except if it is combined with an element of higher electronegativity, then its +1 or higher
  21. half reaction for
    SnCl2 + PbCl4 <---->SnCl4 +PbCl2
    Pb4+ +2e- ---->Pb2+

    Sn2+---->Sn4+ +2e-
  22. 2 types of electrochemical cells?
    galvanic (voltaic) and electrolytic
  23. does oxidation occur at anode or cathode? reduction at?
    an Ox / red Cat = Anode oxidation, reduction at Cathode
  24. function of a salt bridge?
    permits the balancing of charge btwn cells
  25. what kind of battery cell has its anode positive
    electrolytic cell
  26. (t/f) electrons always flow from anode to cathode
    true
  27. reduction potential?
    reduction potential is defined as the tendency of a species to acquire electron
  28. Ag+ +e- ----> Ag (s) Eo=+0.80V
    Tl+ +e- ----->Tl (s) Eo=-0.34V

    which one oxides more easily? reduced more easily

    what is the EMF for a Tl and Ag galvanic cell
    Tl+ oxides easier, Ag+ reduces easier

    EMF= Eored +Eoox=.80+.34=1.14V
  29. formula for standard free energy of electrochemical cell
    • delta G= -(number of moles)(Farady's constant)(EMF)
    • =-nFEocell
  30. whats a faraday (F)?
    amount of charge contained in on mole of electrons =96,487 C.
Author
allenwhycheng
ID
59597
Card Set
MCAT CHEM 3
Description
studying to be a doc
Updated