[chem] Dichtl's clarifications on electrolysis intro

diff --git a/chem/electrochemistry.md b/chem/electrochemistry.md
index 8436dd6bf9070702684fcdc55d6f27d8ca41884e..7996a2413f22f323a1230efcc614987089246082 100644 (file)
--- a/chem/electrochemistry.md
+++ b/chem/electrochemistry.md
@@ -56,6 +56,8 @@ Usually one member of pair is used as electrode (except for *inert electrodes*,
 
 ## Electrochemical/galvanic cells
 
 
 ## Electrochemical/galvanic cells
 

+Spontaneous reaction
+

 1. Find two half reactions involved (between electrode and solution)
 2. Higher equation will proceed left to right
 3. Lower equation will proceed right to left
 1. Find two half reactions involved (between electrode and solution)
 2. Higher equation will proceed left to right
 3. Lower equation will proceed right to left


@@ -82,9 +84,21 @@ Used for vehicles/long-lasting applications. ce{H2} may be replenished.
 
 ## Electrolysis reactions
 
 
 ## Electrolysis reactions
 

+- Occurs when electricity passes through ionic compound or electrolyte solution

 - Opposite of reactions in electrochemical (galvanic) cells
 - Non-spontaneous
 - Electrical energy $\rightarrow$ chemical energy
 - Opposite of reactions in electrochemical (galvanic) cells
 - Non-spontaneous
 - Electrical energy $\rightarrow$ chemical energy

+- Anode +ve; cathode -ve
+- Cathode & anode swap relative to galvanic cell
+- Molten e.g. ce{Na+(l)} vs electrolyte e.g. ce{Na+(aq)}
+- Molten - use echem series to determine probability of electrolyssis of solution or water
+- Min voltage = e_oxidising - e_reducing
+
+### Factors affecting electrolysis
+
+- concentration of electrolyte
+- - e- values must be "close" for electrolysis rxn to prevail over \ce{H2O}
+- nature of electrodes

 
 ### Electroplating
 
 
 ### Electroplating