Rates of Reaction
1
There are four main factors that affect the rate of reaction. These are:
a) C......................... . This is a measure of how crowded the particles are in a solution and the
frequencies of c........................ .
b) S........................ a......................... . This is a measure of how much solid is exposed to reaction
and therefore how many c............................... take place.
c) T......................... . This affects the energy of the particles and how quickly they c...................... .
It also affects the f................... with which the particles collide and how e.............................. the
collisions are. The energy required for any reaction to take place is called the a.........................
energy for that reaction.
d) The presence of a c............................ . These speed up a chemical reaction but is
u............................. chemically. They work by lowering the activation e..................... for the
reaction.
2. Draw lines on these graphs to show how the rate of each reaction changes.
Volume
of gas
produce
d (ml)
Volume
of gas
produce
d (ml)
Time (s)
Time (s)
Draw a line for a reaction happening at
Draw a line for a reaction happening at a
a high temperature and a line for one
high concentration and a line for one at a
at a low temperature. Label each line.
low concentration. Label each line.
Volume
of gas
produce
d (ml)
Volume
of gas
produce
d (ml)
Time (s)
Time (s)
Draw a line for a reaction with a
Draw a line for a reaction happening with
catalysts and one without. Label each
a big surface area and a line for one at a
line.
small surface area. Label each line.
3. Which of the two graphs shows the amount of product during a reaction and which one
shows how much reactant there is?
4. Colour code the boxes to match up a set of 3. The first one has been done for you.
Reaction rate
increases when
a catalyst is
used
This means that there is a
bigger area of a solid
exposed, so there is a
greater chance of collisions
causing a reaction.
People dancing at a
party are more likely
to bump into each
other than people
sitting down.
Reaction rate
increases when
temperature is
increased
Small particles have a
greater overall area than the
same amount of big particles.
This means there are more
particles exposed so more
collisions can happen.
If you have 100
people, they are more
likely to bump into
each other if in this
classroom compared to
the field.
Reaction rate
increases when
pressure is
increased
Catalysts lower the
‘activation energy’ of a
reaction, allowing it to
happen with less energy
input.
If you lower the bar
in a high jump
competition, more
people can get over
it.
Reactions go
faster when
the surface
area is
increased.
If particles move faster,
there is more chance of them
bumping into each other and
therefore of a collision
resulting in reaction.
A lot of children in a
room are more likely
to bump into each
other than a few
adults.
Rate of
reaction
increases when
particle size
gets smaller.
If there are more reacting
particles in a given volume,
then there is a greater
chance of them bumping into
each other.
Chips fry faster than
potatoes because the
oil can cover a bigger
area
Reactions
speed up when
the reactants
are more
concentrated.
Reacting particles get pushed
closer together so there is
more chance of a successful
collision happening.
More dodgems on the
track means that you
are more likely to
bump into someone than
if there were only 2
or 3