Andrew's git / notes.git /
30a6df1f892512beb810f698994ddfe7abed4bab
   1# Chemical energy
   2
   3Chemical energy = heat content = enthalpy
   4
   5$$\Delta H = H_{\text{products}} - H_{\text{reactants}}$$
   6
   7**Exothermic** - energy released from system  
   8**Endothermic** - energy absorbed by system
   9
  10Must specify states (latent heat)
  11
  12## Thermochemical equations
  13
  14$\Delta H$ notates energy change (i.e. kJ / mol)  
  15Exothermic - negative $\Delta H$
  16
  17## Calorimetry
  18
  19$$E = mc \Delta T$$
  20
  21$$\text{calibration factor} = {E \over \Delta T} = {VIt \over \Delta T} \quad \text{J/K}$$
  22
  23## Fuels
  24
  25Substance used for energy production by **combustion** (exothermic)  
  26Fossil fuels - decaying organic material (e.g. coal, petrol, nat. gas)
  27
  28### Efficiency
  29
  30$$\text{% efficiency} = {\text{energy obtained in desired form} \over \text{energy available before conversion}} \times 100$$