A reaction between Hydrochloric Acid and Magnesium ribbon.
Introduction
In a reaction between Hydrochloric Acid and Magnesium ribbon, the Hydrochloric Acid will dissolve the Magnesium ribbon and produce Hydrogen gas.
All chemical reactions involve reactants which when mixed may cause a chemical reaction which will make products.
In case the reactants are hydrochloric acid and magnesium ribbon. The chemical reaction takes place when the magnesium ribbon is dropped into the hydrochloric acid. The products that are formed during this reaction are hydrogen gas and magnesium chloride.
The formula equation for this experiment is:
Mg + 2HCl MgCl2 + H2
The word Equation for this experiment is:
Magnesium + Hydrochloric acid Magnesium Chloride + Hydrogen
(s) (aq) (aq) (g)
Magnesium will react with hydrochloric acid, because it is higher in the reactivity series that hydrogen. When the two chemicals react a displacement reaction will take place and the magnesium will displace the hydrogen in the hydrochloric acid forming magnesium chloride and hydrogen gas.
Depending on certain factors the rate that this reaction will take place will either increase or decrease. The factors that may affect the rate of reaction are as follows:
* Temperature of the Hydrochloric Acid
* Mass of the magnesium ribbon used
* Concentration of the Hydrochloric acid
* Surface area of the magnesium ribbon used
All of these factors will change the rate of reaction because of the Collision Theory. This is a theory that is used to predict the rate of a reaction. The Collision Theory is based on the idea that for a chemical reaction to take place, it is necessary for the reacting particles to collide with each other with enough energy to break or form new bonds between the other particles, which are called a successful collision. During collision if when they collide and they do not have enough energy to break or form new bonds then they will simple bounce of each other, causing an unsuccessful collision.
Aim
To investigate the rate of reaction between Magnesium ribbon and Hydrochloric acid, and see if, by altering the concentration of hydrochloric acid affects the speed of reaction.
Scientific Knowledge
All substances are made up of particles. In liquids there is a space between two particles, in view of the fact that in liquids the particles are not so closely packed together. In gases the particles are really distant from each other, and there is a substantial gap between two particles. Nevertheless, in solids particles are very closely packed together and there is no ...
This is a preview of the whole essay
Aim
To investigate the rate of reaction between Magnesium ribbon and Hydrochloric acid, and see if, by altering the concentration of hydrochloric acid affects the speed of reaction.
Scientific Knowledge
All substances are made up of particles. In liquids there is a space between two particles, in view of the fact that in liquids the particles are not so closely packed together. In gases the particles are really distant from each other, and there is a substantial gap between two particles. Nevertheless, in solids particles are very closely packed together and there is no room or gap between two particles in solids.
Kinetic Theory
The properties of substance- regardless of the state the matter is in- gas, liquid or solid. The word kinetic comes from the Greek "kinetikos" meaning moving. So the kinetic theory is based on the idea that particles of matter are always in motion and that this motion has consequences.
Collision Theory
The Collision theory explains how chemical reactions occur and why rates of reaction differ. For a reaction to occur, particles must collide. If the collision causes a chemical change it is referred to as a fruitful collision.
It's the Theory that explains how chemical reactions take place and why rates of reaction alter. For a reaction to occur the reactant particles must collide. Only a certain fraction of the total collisions cause chemical change; these are called successful collisions.
The successful collisions have sufficient energy (activation energy) at the moment of impact to break the existing bonds and form new bonds, resulting in the products of the reaction. Increasing the concentration of the reactants and raising the temperature bring about more collisions and therefore more successful collisions, increasing the rate of reaction.
When a catalyst undergoes collision with the reactant molecules, less energy is required for the chemical change to take place, and therefore more collisions have sufficient energy for reaction to occur. The reaction rate therefore increases.
Prediction
Based on the scientific knowledge and based on the diagram which explains the collision pattern in low and high concentration. I predict that the more concentrated the acid the faster the reaction will take place because the more concentrated the acid is the faster the magnesium will react and more hydrogen gas will be given off in a quicker time. The basis for my prediction is pretty understandable, because as my scientific knowledge shows, in higher concentration of Hydrochloric acid there is more possibility of particles with Activation energy colliding and starting a reaction as compared to Lower concentration of Hydrochloric acid.
Apparatus
Measuring Cylinder:
Conical Flask:
Cork and a Bent Tube:
Stand:
Clamp:
Ground Glass Syringe:
Hydrochloric acid (Hcl) starting from 0.25, 0.50, 0.75. 1.00 And 1.50:
Magnesium (Mg) ribbon, each one 4cm in length:
Stop Watch:
Fair test
We have to make sure that we use the similar size, amount and roughly the same mass of magnesium, this is because we want to keep the ribbon roughly the same all the way through out the experiment so that it will be a fair test and the results will be related to each other, otherwise the results will be completely different to what we expect and it will be, and it will ruin the experiment.
Safety
Before conducting the experiment we must make a few safety precautions, for our own health and safety. Being careful and aware will prevent accidents from happening. Here are a few things we must make sure we do:
* Wear goggles to protect the eyes.
* Avoid spilling the acid onto your skin as it is corrosive. If it gets in contact with skin was thoroughly with water and seek medical assistance if necessary.
What are we going to change?
In this experiment we are going to change the concentration of hydrochloric acid.
0.25 Molar = Weakest Concentration
0.50 Molar
0.75 Molar
.00 Molar
.50 Molar = High Concentration
Method
DIAGRAM OF THE EXPERIMENT
When doing my experiments I will use the same procedure throughout. Once I have set up the apparatus as shown above, I will start with 0.25 concentration of Hcl and increase by 0.25 each time until I reach 1.50 and I will measure the acid using a measuring cylinder and then pour it into a conical flask. And just before I proceed I will make sure that the syringe is at its starting point. Then I will be ready with the stopwatch and then quickly drop in the ribbon into the acid and place the cork, and start the stopwatch and also observe the readings on the ground glass syringe.I must record the results in a table and then write it up neat later. Before moving on the next concentration I will make sure that I clean the conical flask with water. The factors, which may affect how well the experiment works, are how quickly the ribbon is placed in and the stopwatch pressed. Although this is a factor it is not really a major factor that will affect the end results, and as long as the time it all takes is kept constant throughout then it should not matter too much.
Table of Results
Above is a table showing us the results that I have obtained after conducting the experiment. It shows the volume of hydrogen gas produced when magnesium and hydrochloric acid react. But there seemed to be some anomalous results when reacting Magnesium copper with 1.5 molar solutions of hydrochloric acid.
Evaluation
I think that the experiment went very well. From looking at my results I can see that there were no poor results, which was a good thing, and it proves that everything went very well. Even though the experiments went very well I decided to repeat one concentration of acid again just to see if I could repeat the experiment and get roughly the same results. There was no real source of error in the apparatus along as it all was working well and the way it should have been. The only possibility was the stop watch; it didn't give us the accurate timings as we couldn't stop it exactly at 30seconds every time. Even though the experiment went very well, we could have still improved the method, by the time we close the lid (cork) we have loss of hydrogen gas, due to a reflex reaction.
One Method which would have given us more accurate results is as follows:
Conclusion
My results table and graph show me that when I increase the concentration of the hydrochloric acid, the initial rate of reaction also increases.
Altogether I tested 5 different concentrations of hydrochloric acid. 0.25M, which was the lowest concentration of acid that I used. And increase by 0.25 each time until I reach 1.50M hydrochloric acid, which was the highest concentration that I used, produced the fastest rate of reaction. I repeated all 5 concentrations three times to make sure that they were reliable results and in all cases the higher the concentration the higher the rate of reaction. I have already stated this in my prediction had stated this in my prediction.
As we look at the graph we can clearly see that in all five results at the beginning the reaction happened more quickly than at the end where we can see that it started to tail off. The graph clearly shows how reaction rate of reaction increases when the concentration level is increased.
Kartik Ganeshan Science Coursework
Yr - 11 Rates of Reaction
