Plan:
We want to do an experiment to find out how the concentration of Hydrochloric acid affects the rate of reaction with Calcium Carbonate chips.
CaCo + HCl CaCl +Co +H O
In this experiment we will be changing only one thing the concentration of the Hydrochloric acid; we will do it for five different concentrations, 0.5m, 0.75m, 1m, 1.25m and 1.5m. For each of these we will repeat the experiment three times. We will carry out this experiment for a minuet.
Equipment:
One Measuring Cylinder, (large)
A container of water,
One conical flask,
One delivery tube,
One retort stand and
A stop watch.
Diagram:
To perform this experiment we will first need to fill the container with water, about half way. We also need to fill the measuring cylinder with water until it is full to the top we then attach the delivery tube to the conical flask as shown in the diagram and place the delivery tube in the container which is filled with water. Then carefully, without letting any air into the measuring cylinder we place our hand over the top of it and tip it up side down and place that also in the container, we then place the delivery tube underneath the measuring cylinder. This will allow the carbon dioxide to travel from the conical flask where the reaction is taking place, to the measuring cylinder where we will be able to see how much carbon dioxide has been produced therefore we will be able to see how reactive the acid was.
To make his a fair test we will keep all the equipment the same and will use the same amount of Calcium Carbonate chips ( ) We will also use the same amount of time to carry out the experiment. The only thing we will change is the concentration of the acid: o.5m, 0.75m, 1m, 1.25m, 1.5m.
In this experiment the reason why we get a reaction is because of the collision theory, which is, when the acid is added to the CaCo chips the particles will collide together and the particles will have enough energy so they will react:
Here are the results of our experiment:
We can see from this table of results that as we add a stronger amount of Hydrochloric acid to the Calcium Carbonate chips the reaction increases and the reaction ends sooner than 60 seconds. This means that my prediction was true;
This reaction will be caused by particles colliding with one another, this is because the concentration in the solution has been increased and that means there will be more particles. This means there will be a higher chance of a reaction. (Kinetic energy) The particles must collide with a certain minimum energy, called the activation energy.
Every time we add a higher concentration of acid to the Calcium Carbonate chips there will be a more violent reaction.
Low concentration High concentration
of acid. of acid.
Not very reactive Extremely reactive.
Not many particles Many particles.
We can also see this from the graph, as the gradient of the line increases the rate of reaction also increases. The particles have gained energy and collide together causing a reaction to occur, this is kinetic energy.
As I have stated in the introduction there are many things that also affect the rate of reaction, here is a table showing what and how it happens:
Evaluation:
This experiment went according to plan but there were a few results that I would of liked to test again, they are circled in red:
I feel other things could have been done to this experiment to ensure accurate results.
I felt the measuring cylinder was hard to read the measurements off and instead we should of used another piece of apparatuses.
There was most probably human error in taking the time and reading the measurements.
I would of liked to see how particle size affected the rates of reaction, I have written out a plan to carry out this experiment.
Plan for Particle size and how it changes the rate of reaction:
In this experiment we want to find out how particle size affects the rate of reaction between Calcium Carbonate and Hydrochloric acid, (CaCo , HCl)
CaCo + HCl CaCl +Co +H O
Prediction:
I think if we reduced the size of the calcium carbonate chips and used powder the reaction would increase. This would be because the surface area is increased, giving a greater area for collisions to take place and so causing an increase in the rate of reaction.
I think that the powder will react more vigorously with the acid than the larger chips. The powder has a larger surface area and so is exposed to many more collisions.
Equipment:
One Measuring Cylinder, (large)
A container of water,
One conical flask,
One delivery tube,
One retort stand,
A stop watch,
A fixed rate of Hydrochloric acid.
Diagram:
Fair Testing:
To keep this experiment a fair test we will keep all apparatus the same and us the same concentration and amount of Hydrochloric acid. The only thing that will be changed is the amount and size of the Calcium Carbonate chips. (Large, Medium, Powder)
