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The Haber Process

Reversible Reactions.

When a reaction is reversible,
it means that it can go both forwards and backwards.

The forward reaction is the one we want,
in which reactants are converted into products.
The backward reaction is where the products
become changed back into the original reactants.
Reactions in both directions occur at the same time.

If the forward reaction is exothermic
then the backward reaction is endothermic.
The amount of heat (energy) transferred in
the forward reaction is the same as the amount of
heat (energy) transferred in the backward reaction.

In a closed system, after awhile an equilibrium mixture
is reached where a certain proportion of the mixture
exists as reactants and the rest exists as products.
A closed system means that none of the products or
reactants can escape to the outside environment.
It is like being inside a bottle with a cork in the top.

The term closed system has a different meaning in physics.

When equilibrium has been reached,
it does not mean that the reactions have stopped.
It means that the forward reaction is making products
at the same rate that the backward reaction is
making reactants. It is said to be a dynamic equilibrium.
Dynamic means moving or changing. The word dynamic
reminds you that the reaction has not stopped.

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