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VISUAL CHEMISTRY
HYDROGEN: AS A
PRODUCT OF REACTIONS
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Two reactions that make
hydrogen gas |
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1.
Reacting methane gas (natural gas) with water (as
steam)
This is a reversible
reaction. To make it move to the right there has
to be increased pressure (30 times the pressure
of the atmosphere) and this elevates the
temperature to 900°C. A catalyst is also used. In
this case the catalyst is made from the metals
nickel and chromium. The catalyst is not changed
during the reaction but it speeds up the rate of
the reaction. In this case that is because it
adsorbs the molecules of methane and water to its
surface where the are closer together and react
more easily.
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CH4
+ H20
 CO
+ 3H2 |
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2. From the reaction of
a metal with dilute acid
The metals used to prepare hydrogen
gas are usually zinc, magnesium, calcium or iron.
Any dilute acid can be used.
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Zn +
2HCl
ZnCl2
+ H2 |
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Zn + H2SO4
ZnSO4
+ H2 |
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