Chemistry AS DF CI 4.2
- Created by: A.B.
- Created on: 30-11-13 14:25
View mindmap
- DF Bond Enthalpies CI 4.2
- Bond Enthalpy and enthalpy cycles
- Bond enthalpy is the average energy required to break the bonds of 1 mole of gaseous compounds.
- Bond breaking takes in heat so is positive
- Bond making gives out heat so is negative
- The calculated value is not exactly the same as the quoted value because:
- A bond enthalpy is an average energy needed to break that particular bond and is not specific to the molecule in an equation.
- Bond enthalpies are for gaseous molecules and this may not be their standard state (the state at 298 K and 1 atm)
- Bond strengths
- The greater the bond enthalpy, the stronger the bond.
- Short bonds are stronger than long bonds.
- C=C is shorter and stronger than C-C.
- Bond Enthalpy and enthalpy cycles
Comments
No comments have yet been made