How is a reversible reaction represented
What Are Reversible Reactions? | Reactions | Chemistry | FuseSchool
in this lesson we will learn about
reversible reactions when we fry an egg
it is impossible to on fry it a lot of
reactions work in the same way once it
is done it is irreversible a good
example is the combustion of magnesium
to form magnesium oxide reversible
reactions are reactions where formed
products can revert or go back to their
original reactants since the reaction
can proceed in either direction we use
this reaction arrow to represent
reversibility an example of a reversible
reaction is the thermal decomposition of
ammonium chloride to form ammonia and
hydrogen chloride place ammonium
chloride in a boiling tube and heat
using a Bunsen burner ensure that this
is conducted in a fume cupboard as
ammonia and hydrogen chloride are both
corrosive gases if we hold red litmus
paper at the mouth of the boiling tube
it turns blue which confirms the
presence of ammonia blue litmus paper
turns red which confirms the presence of
hydrogen chloride remove the boiling
tube from the heat and let cool have a
look near the mouth of the boiling tube
you will see that there are white
crystals these are ammonium chloride
crystals so what has happened here
ammonium chloride has thermally
decomposed to ammonia and hydrogen
chloride the formed ammonia and hydrogen
chloride have reacted to produce
ammonium chloride therefore this is a
reversible reaction why is the thermal
decomposition of ammonium chloride
sometimes incorrectly called a
sublimation reaction please pause the
lesson to think about this and resume
when you are done
here is a hint think about phase changes
and what happens to a substance during a
phase change when a substance goes from
the solid phase to a gas phase it is
said that it has sublimed this phase
change is not a reaction as the
substance itself has not changed in our
example solid ammonium chloride did not
form a gaseous ammonium chloride but
rather it decomposed under heat to form
ammonia and hydrogen chloride therefore
it is not a sublimation reaction
