I just need someone to answer the question please
If you increase the number of atoms in fuels why do we get more heat energy HELP PLE Watch
The Lonely don
- Thread Starter
- 27-01-2015 22:03
- 27-01-2015 22:33
Increasing the number of atoms in fuels means that there are more atoms to react together to produce energy. The kinetic energy applied when fuel is combusted would be applied to a greater number of molecules, increasing the chances of a successful collision (as there are more of them to collide). The products of combustion are heat/energy, so adding more atoms would push the equilibrium to the right hand side (to completion) because the system always tries to counteract any change you make.
I think this is right, but I'm not that good at chemistry... I'd check with a chemistry teacher.
- 27-01-2015 22:39
More atoms within a molecule means that the combustion reaction uses more other reactants (oxygen) and produces more products(carbon dioxide and water) this makes the enthalpy change of combustion more negative, so more heat energy is given out.
If you meant more molecules, each mole of the fuel contributes heat energy equal to the modulus of the enthalpy change of combustion. If you increase the number of moles, then more energy is contributed.
Most of what Cyanide said was ok, but for a reaction that goes to completion, there is nothing you can do to change the composition of equilibrium. The reaction will always go to completion.
- 27-01-2015 22:48
Yeah, actually, that was only for reversible reactions (ones that don't always go to completion). Combustion isn't one.
I dont think you need an awful lot of detail for GCSE though, so don't worry.Last edited by Shannonleah; 27-01-2015 at 22:50.