Electrochemistry + Past Review

• If Q > Ksp, does precipitation happen or no?

  Precipitation occurs
• If Q < Ksp, does precipitation happen or no?

  No precipitation occurs
• The amount that precipitations out: Equilibrium calculations for determine concentrations that...

  precipitates out
• The amount that precipitates out: Use ___ volume to convert concentration change to moles or mass that precipitates out

  solution
• What is the common ion effect?

  The solubility of a salt in a solution that already contains one of the ions in the salt will be lower than in pure water (solvent)
• Lewis base ___ e- pair used to form dative (coordinate covalent) bonds

  donates
• Lewis acid ___ e- pair used to form dative (coordinate covalent) bonds


  accepts
• Formation constant: kf =

  [Ag(NH3)2+] / [Ag+][NH3]2
• Dissociation constant: kd =

  [Ag+][NH3]2 / [Ag(NH3)2+]
• What is electrochemistry?

  The study of the relationship between electricity and chemical reactions.
• What is a battery?

  A single metal/electrode/metal set-up makes a galunoic of cell (multiple connected together makes a battery)
• What is a redox reaction?

  a chemical reaction in which electrons transfer between reactants, resulting in a change in oxidation states.
• OIL RIG mnemonic stands for...

  oxidation is losing (e-), reduction is gaining (e-)
• Oxidation number = charge only for

  atomic ions
• All pure elements have an oxidation number, even for O2 =

  zero
• O atoms in compounds usually have an oxidation number of...

  -2 (besides peroxide H2O2 where it is -1)
• Alkali metals = ?, Alkali earths = ?, Halogens = ? (but in oxides +1, +2...., in CIO-, Cl is +1)

  +1, +2, -1

  
• What is an oxidation reaction?

  Loss of electrons.
• What is a reduction reaction?


  A reduction reaction is a chemical reaction in which a molecule or ion gains electrons, resulting in a decrease in its oxidation state.
• What is a standard half-cell potentials

  an electrode with a stable and well-documented electrochemical potential voltage.
• most positive reduction potential goes...

  as written
• What is a cathode?

  Negative electrode.
• What is an anode?

  Positive electrode.
• Reduction: M^n+ + n(e-) --> M has E..

  Ered
• M --> M^n + n(e-) has E...

  -Eoxidation
• Ecell = Erod + Eoxid Ecell =Ecathode - Eanode Ecell = l?l


  l E1-E2 l
• Delta G = nFE, what does n stand for?

  number of moles e- transferred in reaction
• Delta G = nFE, what does F stand for?

  Faraday constant, 96485 C/(mol e-) = 96485 JV-1(mol e-)-1
• Delta G = nFE, what does E stand for?

  Cell potential (not necessarily under standard conditions)
• Are cathode cations or anions?

  Cations
• What are anodes about their species?

  Neutral species are oxidized
• Is higher reduction potential spontaneous?

  Yes, lower reduction potential is not spontaneous
• What does -deltaG mean?

  Spontaneous, you do work
• What does it mean when Ecell = 0

  very dead battery, G=0 at equilibrium so no work is available
• What does Q stand for?

  product/reacant when substances not solids or water
• How do you calculate the equivalence point?


  Do full equilibrium
• Lower Ered for R means

  the greater the reducing power of R
• Higher Ered for R

  The greater the oxidizing power of O
• What does -DeltaG mean in relation to cell potential and K

  Forward redox reactions is favored, cell potential is positive, at equilibrium products > reactants so K is large deltaG < 0, E>0, K>1
• What does +DeltaG mean in relation to cell potential and K

  reverse redox reaction is favored, cell potential is negative, at equilibrium reacants > products so K is small DeltaG > 0, E<0, K<1