(Note: Some words can be repeated)
a. Combustion reactions occur at very different rates. The reaction will be increases when
large lumps of coal and a limited supply of air is used. This is because the burning only
takes place on the
of the coal. When the coal is ground into very fine particles
the reaction is
because there is a large
area of fuel exposed to the
oxygen. In diesel engines the liquid fluid reacts within a few milliseconds producing an
which is an extremely rapid reaction.
b. Combustion is just one example of chemical reaction which occurs at different rates. One
factor that determines the speed rate at which a reaction occurs is the
energy.
Usually slow reactions have
values for this. Chemists alter the rate at which a
reaction occurs by changing one or more of the following factors:
size of the
or by using a
Increasing the rate at which
c. For any reaction to occur the reacting particles must
this occurs will
the rate of the reactions.
per unit volume. Increasing the
d. Concentration is a measure of a number of
concentration means there are
particles per unit volume so the chance of collisions
between particles
and this, in turn, increases the reaction rate.​