From 05a7290991f846c5d6dbb5221164c834f4add483 Mon Sep 17 00:00:00 2001
From: Andrew Lorimer <andrew@lorimer.id.au>
Date: Thu, 3 Jan 2019 23:10:25 +1100
Subject: [PATCH] add more notes on energy (already studied in 2k18)

---
 chem/energy.md | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/chem/energy.md b/chem/energy.md
index c532be1..30a6df1 100644
--- a/chem/energy.md
+++ b/chem/energy.md
@@ -9,8 +9,22 @@ $$\Delta H = H_{\text{products}} - H_{\text{reactants}}$$
 
 Must specify states (latent heat)
 
+## Thermochemical equations
+
+$\Delta H$ notates energy change (i.e. kJ / mol)  
+Exothermic - negative $\Delta H$
+
 ## Calorimetry
 
 $$E = mc \Delta T$$
 
-$$\text{calibration factor} = {E \over \Delta T} = {VIt \over \Delta T} \quad \text{J/K}$$
\ No newline at end of file
+$$\text{calibration factor} = {E \over \Delta T} = {VIt \over \Delta T} \quad \text{J/K}$$
+
+## Fuels
+
+Substance used for energy production by **combustion** (exothermic)  
+Fossil fuels - decaying organic material (e.g. coal, petrol, nat. gas)
+
+### Efficiency
+
+$$\text{% efficiency} = {\text{energy obtained in desired form} \over \text{energy available before conversion}} \times 100$$
\ No newline at end of file
-- 
2.47.1