From: Andrew Lorimer <andrew@lorimer.id.au>
Date: Thu, 18 Apr 2019 06:58:40 +0000 (+1000)
Subject: [chem] electrolysis intro
X-Git-Tag: yr12~167
X-Git-Url: https://git.lorimer.id.au/notes.git/diff_plain/b0d3855697cc5e735e63eb2e9776333f3b9a466c

[chem] electrolysis intro
---

diff --git a/chem/electrochemistry.md b/chem/electrochemistry.md
index e439add..8436dd6 100644
--- a/chem/electrochemistry.md
+++ b/chem/electrochemistry.md
@@ -80,3 +80,29 @@ Used for vehicles/long-lasting applications. ce{H2} may be replenished.
 - **Alkaline fuel cell** - ce{KOH(aq)} electrolyte, ce{H2(g)} from tank, ce{O2(g)} from atmosphere, water out of hydrogen side
 - **Acid fuel cell** - ce{H3PO4} electrolyte, water out of oxygen side
 
+## Electrolysis reactions
+
+- Opposite of reactions in electrochemical (galvanic) cells
+- Non-spontaneous
+- Electrical energy $\rightarrow$ chemical energy
+
+### Electroplating
+
+- For each ion going into plated object, an ion is replaced from the anode (+ve)
+- Electrolyte balances charges
+
+### Coulomb's law
+
+$$Q=It$$
+
+### Faraday's first law
+
+$$m \propto Q$$
+
+i.e. mass produced at cathode is proportional to charge supplied
+
+*Faraday* - charge on 1 mol of electrons = 96500 C.
+
+### Faraday's second law
+
+> To produce one mole of substance by electrolysis, a whole number of mole of electrons is needed