click below
click below
Normal Size Small Size show me how
CHEM 113- Unit 5
| Question | Answer |
|---|---|
| ΔG when K is small | positive (non-spontaneous) |
| ΔG when K is large | negative (spontaneous) |
| redox reactions- acid solutions | balance O with H2O, balance H with H+ |
| redox reactions- basic solutions | remove H+ with OH-, reconcile H2O's |
| anode | oxidation (metal breaks down, more ions added to solution) |
| cathode | reduction (metal builds up, ions removed from solution) |
| salt bridge | allow transfer of ions (anions toward anode; cations toward cathode) |
| inactive electrodes | electrodes made of something different than the solutions but still transfer electrons |
| 2 most common inactive electrodes | carbon, poladium, platinum |
| voltaic cell notation | inactive electrode|lower ox state|higher ox state||higher ox state|lower ox state|inactive electrode |
| Ecell= | cathode-anode |
| Voltaic cells are spontaneous when | Ecell>0 |
| Reduction potential is based off of | standard hydrogen electrode |
| metal activity | higher reduction potential=higher activity |
| concentration cell | same metal at the anode and cathode-> differ in concentration (anode is always lower) |
| electrolytic cell | external source of power must be greater than Ecell for the forward reaction |
| sign of oxidation in an electrolytic cell | + |
| sign of reduction in an electrolytic cell | - |
| molten salts: what forms at the anode | LESS electronegative non-metal |
| molten salts: what forms at the cathode | MORE electronegative metal |