Zusammenfassung der Ressource
Energetics
- Bonds Made
- energy realeased
- combustion of fuels
- oxidation of C6H12O6
- exothermic
- negative enthalpy
- Bonds Broken
- Enothermic
- Positive ethalpy
- Absorbs Energy
- Thermal decompositon of CaC03
- Photosynthesis- sunlight supplies E
- Standard enthalpy change of reaction
- Is enthalpy change when 1 Mol reacts under
standard conditions of their standard states.
- Bond enthalpy
- accurate
- as bond actually exists
- O=O
- Mean Bond enthaply
- is the energy need to break (or dissociate) a
bond averaged over many different molecules.
- when bonds actually exsist on there own
- C-H
- Enthalpy Change
- Heat energy transferred in a reaction
at constant pressure in KJmol^1
- ΔH=sum of(bonds broken-bonds made)
- Always give KJmol^1 to 1 d.p
- -126.0 KJmol^1
- Exothermic
- +267 KJmol^1
- enothermic
- Standard Enthalpy changeof formation
- enthaply change when 1 Mol of a compound is formed from its
elements in their standard states under standard conditions
- i.e 2C+ 3 H2 +0.5O2 --> C2H5OH
- Standard enthalpy change of combustion
- enthalpy change when 1 Mol of a substance is completely burned
in Oxygen under standard conditions