Rates of Reaction Experiment
Length: 1512 words (4.3 double-spaced pages)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This experiment is called ‘rates of reaction’, I will be partaking in
this experiment to find out what factors effect the ‘rate of
reaction’ between magnesium (strips) and hydrochloric acid. Each time
I repeat the experiment, I will be adding 0.5 moles of hydrochloric
acid and recording the volume of gas given out during the testing and
record the time it takes to give the reaction needed. A reaction is
taken place within the experiment because there is a collision of
particles in each element. When these two elements collide with each
other they form a chemical reaction ( a change which is irreversible)
we know this because a gas is given of too show a change, this is why
we record the amount of gas given off to show when the reactions takes
place and how big of a change it has made.
Magnesium + Hydrochloric Acid à à Magnesium Chloride + Hydrogen Acid
Mg + 2HCl H2 + MgCl2
Activation energy is the minimum amount of energy, which the particles
must have in order to react.
There are five factors, which can make a difference to the rate of a
*1* The surface of the element
*2* Catalyst, the amount of the substance
*3* The concentration of the element
*4* Temperature, due the heat of the atmosphere
*5* Pressure pronounced to the substance
When a reaction takes place, the substances used are called reactants
and the substances produced are called products. Because the amount of
products being produced are increasing the number of reactants are or
should be decreasing.
To calculate if and how well products are increasing and reactants are
decreasing we use a number of ways, we firstly find out how much of
the reactant(s) is being used up and how much product(s) we are
gaining from this in a set time.
FORMULARS TO SOLVE THIS:
*** How much reactant is being used up***
Amount of reactant being used up
Reaction rate = Time taken
***How much product’s being produced in a set time***
Amount of product formed
Reaction rate = Time taken
A reaction can only take place when a successful collision is
occurred, so for a reaction to take place two different elements have
to concur with each other, this depends on the amount of atoms and
energy in the two elements, this is called a successful collision. A
chemical reaction can only take place when two different elements
collide with each other.
There are other methods to measure the rate (speed) of reaction.
Precipitation: observe a marker through the solution and predict how
long it takes to vanish.
A change in mass: a mass balance can only be carried out during the
process. The mass can only be read when the gas is given off.
Volume of gas produced - use a gas syringe to measure the amount of
gas given off.
Our group has made a few predictions based on the Temperature of the
solution, Concentration of the acid, and the Surface area of solid
reactants. I have predicted that an increasing of the temperature,
concentration, catalysts and surface area will speed up the time in
which it takes for the reaction to occur in and increase the total
output volume of gas.
I predicted that an increasing of the surface area will shorten the
time of the reaction taking pace. Outsized particles have a small
surface area in relation to their volume; fewer particles are open to
the elements and available for collisions. This means less collisions
will occur and it would be a much slower reaction.
Small particles have a large surface area in relation to their volume;
more particles are open to the elements and available for collisions.
This means more collisions and a faster reaction.
My prediction is that if you increase the temperature of the solution
the reaction will take place in a faster amount of time. In a cold
reaction mixture the particles are moving quite slowly, the particles
will collide but with less force, and less collisions will be
When the reactants in the mixture is heated the particles will move
more quickly, the particles will collide with each other more
frequently, with superior power, and several collisions will be
I predicted that if you increase the concentration of the acid, the
faster the reaction will occur. In a reaction where one or both of the
reactants are in low concentrations the particles are spread out and
will collide with each other less often resulting in less successful
collisions. In a reaction where one or both reactants are in high
concentrations the particles are crowse together and will collide with
each other more often, resulting in an increased number of successful
A catalysts sbstance, which increases the rate of a chemical reaction,
without being changed during the procedure. Catalysts work by lowering
the amount of energy needed for a successful collision. They are very
specific to a particular reaction and are not used up during the
PREDICTIONS AND THEORY
My prediction that if you increase the concentration of the acid, the
faster the reaction time. This can be supported with this theory. My
theory is that if we were to dilute the solution the particle would
become further apart then they would be in a concentrated solution. An
increase in the concentration will conclude in more frequent
collisions, therefore the more collisions that take place will be
adequately energetic for a reaction to occur.
When doing this experiment we did not increase the temperature but I
still feel with out testing out our theory that my prediction would be
correct on the fact that if I were to increase the temperature and/or
surface area, the reaction rate would be significantly faster. This is
because increasing the temperature causes an increase in the kinetic
energy of the particles (they would move a lot faster and create more
collisions). The minimum energy required for reaction will therefore
occur more often resulting in a greater rate of reaction.
Goggles – Used for safety, to prevent harmful substances from reaching
your eyes and causing permanent eye loss.
Stopwatch – To time how long the reaction took.
Conical Flask – The flask in which the experiment takes place.
Measuring Cylinder/Beaker – Used to measure out 25cm³ of
Dilute Hydrochloric acid.
Syringe – To measure the amount of gas given off.
Safety is one of the most important topics you will learn in science
as it is regarding your health and well being.
Safety is especially important when handling harmful substances such
as Acid. It is compulsory that you take major safety precautions; this
includes wearing safety goggles and over safety wear that may be
avaliable. Some accidents involving harmful substances, such as acids,
can cause permanent injuries such as damaged eyesight this is why
supervisors in the lab advise you and provide you with safety
equipment while carrying out an experiment
All students should always learn all safety rules given by supervisors
even basic safety rules are required to be known.
When my group used Hydrochloric Acid with a concentration of 0.5Moles
the reaction took place much slower than it did when I used a higher
amount of acid. This is visible on my graph as the line that shows the
reaction at 0.5Moles is not very steep. My group found that the
steeper the line the quicker the time that the reaction took place in.
The reason for this is that the hydrogen gas given off was less so it
caused the reaction to take place slower.
The graph I produced shows that when a higher concentration of
Hydrochloric Acid is used the rate of reaction is much faster. When a
lower concentration of Hydrochloric Acid is used the longer it takes
for the gas to be produced. This means that the higher the
concentration of acid the faster the time the reaction will take
place. This is because when using the higher concentrated solution the
reactants are used up quicker in the reaction.
Whilst completing this experiment I have proved that the more
substance used in the reaction (hydrochloric acid) the faster the
reaction will take place. This also shows, the higher the
concentration of the substance the closer the particles would be to
each other so it increases the possibility of collision which would
decrease the time in which the reaction takes to occur, and also the
more particles that are present in the reaction the greater chance
there is for numerous successful collisions.
If I had been given more time to carry out this experiment, I would
have tested every rising concentration of Hydrochloric Acid again.
This would have made the experiment fairer providing more reliable and
I have come to my conclusion by looking at my results and graph that I
have produced. I have also used personal observation to provide
evidence for my decision. My conclusion is that the higher the
concentration of Hydrochloric Acid the faster the reaction.