Chapter 2-DF4 Flashcards
Where does energy come from?
1
Q
What is energy density?
A
How much energy you get per kilogram of fuel
2
Q
How do you work out energy density (kJ kg-1)?
A
ΔHθc / (Mr /1000)
3
Q
What is bond enthalpy?
A
The energy needed to break 1 mole of a bond to give separate atoms, all in their gaseous state
4
Q
Why are bond enthalpies positive?
A
They need energy to break bonds so is endothermic
5
Q
How do you work out the enthalpy from the bonds broken and bonds made?
A
Enthalpy = bonds broken - bonds formed
