Which of the following would not
increase the rate of a reaction according to collision theory? (A) Increasing the pressure, (B)
increasing the temperature, (C) increasing the surface area of particles, (D) using
a catalyst, or (E) using a differently shaped container with the same volume.
The rate of reaction is the rate at
which reactants are converted into the products. Some chemical reactions are
explosive and have incredibly fast reaction rates, while others produce products
such as rust at a slow rate. Collision theory explains why some
chemical reactions happen fast while other happens slow. Collision theory suggests that for
a collision to lead to a reaction, the particles must collide with enough
energy. These collisions also require the
appropriate orientation. This theory also tells us that by
increasing the number of collisions, a greater number of successful collisions is
more likely and so the rate of reaction increases.
Pressure affects the reaction
rate. Highly pressurized particles are
close together and collide more frequently. This can lead to an increase in the
reaction rate. Since the question asks us which
would not increase the rate, we can eliminate answer choice (A).
Temperature also affects the rate
of a reaction. Higher temperature particles move
faster and collide more often. They also collide with more energy,
which increases the likelihood of a successful collision. Increasing the temperature would
increase the rate of a reaction, so we can eliminate answer choice (B).
The surface area of the reactants
can also affect the frequency of particle collisions. When surface area is increased, the
reaction rate can increase as more particle surfaces are available to collide. We can eliminate answer choice
A catalyst lowers the activation
energy barrier of a reaction. This means that less energy is
required for a successful collision between particles to occur, which can ultimately
increase the reaction rate. We can eliminate answer choice
Changing the shape of the container
does not significantly affect the particle collision process. If the containers have the same
volume of space for the particles to occupy, the container shape should have no
effect on how fast the reactants turn into products. Therefore, the container shape
would likely not alter the rate of a reaction.
So, the answer choice that would
not increase the rate of a reaction, according to collision theory, is answer choice
(E): using a differently shaped container with the same volume.