Zusammenfassung der Ressource
C3.3 Energy Calculations
- Comparing the energy
released by fuels
- Calculating energy released
- Energy = mass x specific heat capacity x temp rise
- A calorimeter can compare
energy released
- Energy transfer
in solutions
- The equation works for any fluid
- Energy
level
diagrams
- Energy is measured in
kilojoules per mole
(kJ/mol)
- Exothermic reactions
- Surroundings get hot
- Endothermic reactions
- surroundings get cooler
- Activation energy and catalysts
- Activation energy
is how much
energy is needed
to start a reaction
- Catalysts create an
alternate pathway to the
products so lower the
activation energy
- Bond breaking and bond making
- Endothermic
is breaking
bonds
- Exothermic
is making
bonds
- Calculations using
bond energies
- Bond energy
- Energy
needed to
break a bond
between two
atoms
- Used to work out
the energy change
- Work out energy to break each reactant then how to make product
- We can then tell endothermic or exothermic
- Fuel Issues
- Consequences of burning fuels
- supplies are running out
- CO2 in the air
- Not good
- Hydrogen Powered Vehicles
- Hydrogen + Oxygen => Water
- No global
warming
- safety and
storage issues
- Using electrolysis
still uses fossil fuels
so we must oxidise
it in a fuel cell