The chemical equation for this experiment is
Mg + 2HCl MgCl2 + H2
My prediction on this experiment is when the temperature is kept at low degrees the reaction of magnesium strips with HCl will be slower but when the temperature is raised to a higher degree the magnesium strip will react with HCl much faster. So when the particles move faster they would have more collisions between them. In cold temperature In hot temperature Example when magnesium strip is set to react with HCl at 10 degrees the reaction will be much slower compared to when the magnesium strip is set to react with HCl at 60 degrees.
Preliminary Test I have carried out preliminary test to make sure that my experiment will go right. In my preliminary test we done the same type of experiment which we will be doing for out final one. After conducting this test we found out that the test was correct and so now we could do a real experiment
To find the average number of time taken I had to use a formula which was: Time 1 + Time 2 + Time 3
My predictions were correct that when the temperature increases in a rate of reaction the reaction goes much faster. You can also see this from the table of result on top that at 100 the average time is 60 seconds and when you will look at 800 the reaction took only 37 seconds Accuracy of Results Although there were some anomalous results in my first set of readings I think that overall the accuracy was sufficient for the experiment as the pattern shown by my results and my conclusions are supported by the collision theory.
I think that this experiment worked well, as the results fit with my hypothesis and are supported by the collision theory. Errors There is one suspected anomalous readings in my results from this investigation taken in the first set, for the temperature of 30i?? C (see Table 1) The anomalous readings from the first set give slower reaction rates for increased temperature which is not a trend shown by any other results. The second set of results taken show the trend predicted in my hypothesis of increased reaction rate as temperature increases.
These anomalous readings could be due to a number of reasons as follows: –
We could improve our experiment in many ways such as improving the method of timing how long it takes the ribbon to dissolve by looking at the ribbon very carefully without any distraction and closely using goggles which would help us to know when exactly the ribbon got dissolve. Other improvements could be to do the experiment on a water heater except doing in the bowl because we can keep the temperature at a steady rate, which it needs to be on.
My aim to this experiment is to discover whether different surface area affects the rates of reaction
Fair test In order to keep a fair test, only the surface area (i. e. size) of the marble chips and powder is variable. Other variables are to be kept constant to avoid obtaining wrong results. These other variables include:
The HCl cannot be used again after the reaction because the acid becomes less strong to react with the acid. I need to be accurate in taking my readings as an inaccurate reading may cause errors and alter my results. The surface area of the chips needs to be appropriate and vary in different experiments to get the correct rate of the reacting size The word equation for this reaction is Calcium carbonate + hydrochloric acid calcium chloride + water +carbon dioxide The chemical equation for the reaction
CaCO3(s) + 2HCl(aq) CaCl2 (aq) + H20 (l) + CO2 (g).
I predict that as the size of particles decreases, surface area will increase causing the average collision of particles to increase. Which means that the powdered chips will react faster. An increase in rate of collision causes an equal increase in the rate of reaction. This is based on the collision theory that states that for a reaction to occur between two particles, an effective collision must take place to form product molecules. The reaction rate is the measure of how frequently effective collisions occur.
In chemical reactions, existing bonds in the reactant particles have to be broken down first before new bonds are formed to produce product particles. Reactions only occur if colliding particles have more than a minimum amount of energy. This energy is known as activation energy (EA). It acts as a sort of ‘energy barrier’ unless particles have more energy than the activation energy, the reaction cant take place. As a result, of increase in surface area, I predict that there is greater area for contact between the powder and the acid for reactions to take place therefore increasing rate of reaction.
The rate simply depends on how fast and often particles collide with each other. The increase in surface area also results an increase in the rate of reaction. The most concentrated substances the faster that reaction would be. The more surface area will allow particles to move more freely and have more collisions Small Surface large surface area area the smaller the marble chips are the increase in surface area so it also means reactions has to increase.
From the results of my experiments I observed that each of the reactions start of fast but start to slow down after some time. A reaction is exothermic if heat energy is given out during the chemical change, and the surroundings get hotter.
On the following pages there are two graphs showing the rates at different surface areas. And another graph with both the reaction compared Conclusion In this experiment my aim was to see which type of surface area gives the fastest rate of reaction. I have succeeded in doing so. I recorded the rates of reaction using different sizes of particles. My predictions matched and concluded with my results, as you can tell from the graph, I have proved that the smaller the size of marble chips the faster the rate because the surface area is more and more collisions take place per second.
The particles of hydrochloric acid (HCl) and calcium carbonate (CaCO3) react by colliding with each other. Although the chips are the same mass with powdered chips, it has less surface area. In the graphs, I saw distinct patterns: they all have positive link that illustrates that they all have the same trend. The graphs are more efficient in describing the same effects as that of the tables because it shows clearly that the smaller the size of particles, the faster the rate of reaction. Evaluation I think my experiment was successful as I was able to obtain the evidence I needed to achieve my aim.