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TGV1:
Flames: Hydrogen
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The
story of some flames can be quite involved, so we start at
the simplest case by setting hydrogen alight and build up
to more complex examples later in this topic.
Notes on the video of hydrogen burning
You may find it helpful to pause the video at key points
and ‘step’ through it frame by frame as the
flame is lit by
the hot wire.
The important points are:
• the flame is a chemical reaction between
the hydrogen and the oxygen of the air;
• the hydrogen has to mix with the oxygen;
• the mixture has to be hot enough for the reaction
to start;
• once started, the reaction gives out a lot of energy,
released as heat and light;
• we see the flame because some of the energy is released
as light.
Notes on the hydrogen and oxygen drag animation
You may like to draw attention to the ‘bonds’
disappearing and reappearing on breaking and remaking.
Notes on the simulation of hydrogen reacting with oxygen
This simulates the random motion of the molecules and runs
differently each time: all of the hydrogen and oxygen molecules
will react if given long enough to meet up. This simulation
can also be used to explain why the rate of a reaction slows
down as the reactants are used up.
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Science Enhancement Programme CD-ROM 2005 |
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user
guide |
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