Rate of Reaction between CaC03 and HCL.

Rate of Reaction between CaC03 and HCL

Aim

In this experiment I have the choice to change any variable to see what effects it could have. I am changing the temperature of the hydrochloric acid to investigate the rates of which the Calcium Carbonate reacts with it, and to discover what amount at which temperatures release a more quantity of gas (carbon dioxide). The other variables I could choose from to investigate are:

· Size of the Calcium Carbonate Chips.

· Concentration of the hydrochloric acid-

· How weak or strong it is.

· The temperature of the acid.

· Surface area of the conicle flask.

· Amount of chips.

· Amount of Hydrochloric acid.

The Equation.

Calcium + Hydrochloric ® Calcium + Water + Carbon Dioxide.

Carbonate Acid Chloride

The Chemical Equation

CaCo (s) + 2HCl (aq) ® Ca Cl (aq) + H O +Co (g).

Prediction

I predict that as the temperature rises, the average Speed of particles increases. At high temperatures, there are more collisions per second and this results in an increase in the rate of reaction. A reaction will only occur if the colliding particles possesses more than a certain minimum amount of energy. This minimum energy for a reaction to occur is known as the activation energy. EA. The activation energy enables chemical bonds to stretch and break the rearrangements of the atom, ions and electrons to occur as the reaction proceeds. As a result of the temperature rising I predict that the particles in the marble chips receive more energy and start colliding with each other to increase the reaction, the rate of it simply depends on how hard and often the reacting particles collide with each other. The energy (gas) given off becomes more as the temperature rises, therefore I predict that the reaction using the highest temperature (60°) will produce the highest amount of gas in the slowest time. This I will measure the gas by changing and controlling the rate of carbon dioxide given off during each tests.

Keeping in mind that the acid does not dissolve the marble chips it reacts with them as two separate reactants, the shape of the chips stays the same but after the experiment they cannot be used again because the acid would have used up all the reactant energy to make the gas substance. This is an exothermic reaction. I can prove that this is an exothermic reaction by measuring the finish temperatures of each of the four temperatures I have used, to see if they change or get affected by the start temperature because of how high they are, therefore the end temperature will be less than the beginning temperature.

I predict that the end temperature will become gradually more as the temperature rises because the reaction between the acid and the calcium carbonate releases heat, which gives the particles in the marble chips energy to collide. If it is releasing heat (made by the reaction) it means that a higher temperature needs to be present to make the end substance, which is the gas being made quicker, therefore the finish temperature is going to be higher than the start.

I am only going to time each reaction for 70 seconds, I went up to this point because if I go up any further I predict that it will be producing a faster rate of gas per second for me to count. After the 70 seconds it will have shown me the initial rate. I will take readings every 10 seconds, to measure the amount of gas produced, it will also enable me to see if the reaction is slowing down or speeding up at all. I predict that the higher the temperature rises, the reaction will speed up producing more gas in a shorter space of time.

Based on my own knowledge, if I were to predict the shape of the graph for a certain temperature at this early stage in the investigation, given the amount of gas produced and the time it had taken, I would expect it to look like this;

Comparisons to other Variables

This is a preview of the whole essay

Comparisons to other Variables

Size of calcium carbonate chips- The size will determine the rate of the reaction, if the chips are small like powder, then they would have a larger surface area, therefore the rate would speed up because the bonds would be easier to break up because more of the acid particles will have more access to more of the powder which would make it faster. If the chips were bigger, they would have a smaller surface area overall, this means that the acid will have less area to act on to dissolve.

Concentration of the hydrochloric acid- If the acid is diluted with water it would make it weaker and also slower to react with the chips of calcium carbonate and because there are less particles of the reactant between the water molecules, which would have enabled it to make more collisions and therefore react quicker. Whereas if the solution has a stronger concentration with less water or none at all it would react at a faster rate, this is because there will be more of the particles reacting and colliding at a more faster rate than a solution with a weaker concentration and larger surface area.

The temperature of the acid- The reaction gets its energy from the Heat and temperature it is working at, the heat gives the reaction energy, as this energy is given the particles begin to collide, as the temperature increases as does the amount of energy there is to collide with each of the different substances of particles which will collide the fastest. If the temperature is low there would be less energy given to the particles for more collisions per second and the reaction would either not begin or begin very slowly.

Surface area of the conical flask- If the flask has got a small base, the acid and the marble chips will be more compressed together, meaning that the acid is closer to the chips surrounding it thus covering a larger surface area of particles. With the chips closer together it means that the collisions will occur more often because the particles will not loose their energy traveling to another particle otherwise the collisions will be less.

Amount of chips- If the amount of chips is more than the amount of acid it means that the chips will have less particles of acid between their particles, therefore making an unequal amount of each product, which will slow down the reaction rate. If there were less chips compared to the acid the reaction will be faster because more of the acid will be present for each separate chip and more of the surface area will be covered which means more of the acid will be acting upon it.

Amount of hydrochloric acid- If there is more of the acid compared to the chips(similar to explanation above) more of the acid will be there to react with the chips therefore it will be faster. If there were less of the acid than the chips, little acid will be there to react with the chips therefore it will be slower because less percentage of the acid is there to cover less surface area of the calcium carbonate.

Safety

· Wear Goggles! Acids are very dangerous substances and can cause major skin irritation or burns and can damage eyes if squirted into the eye or pupil cavity.

· When using the acid handle it carefully and with responsibility because it is a harmful product if it comes into contact with the skin!

· The gas syringe need to be watched while collecting the amounts of gas, incase the amount is suddenly too much and the syringe falls out of the end and breaks!

· Marble chips however small or large can be sometimes inhaled or lodged in bodily organs and orifices like eyes and ears or noses. These dangers should be noted however unlikely.

Fair testing

To keep it a fair test, the variables need to be kept the same to prevent getting the wrong results. The temperature of the acid needs to be accurate to get the correct rates of the reacting marble chips. The size of the marble Chips needs to be kept the same because of them either having a larger or smaller surface area for the acid to react with. If it has a larger surface area than the previous chips the results would be wrong because it has a larger area to react with, therefore the time it would have taken would be more than should be. If it were compared to the smaller chips the time would be less because of it having a smaller surface area for the reaction to act on. The Hydrochloric acid cannot be used again after the reaction otherwise the acid will be less strong to act on the marble chips.

When I am reading the syringe for results I need to be accurate in the amount I have observed because it could affect my results.

On each experiment at different temperatures I have to make sure the amount of marble chips and acid are the same each time to help me in getting the best results possible.

Equipment

· Gas syringe

· Bunsen Burner

· Tripod

· Conical Flask

· Gauze

· Measuring Cylinder

· 2 Clamps

· 2 Stands

· Stop clock

· Fireproof Mat

· Thermometer

· Beaker

· Boiling Tube

· Calcium Carbonate (marble Chips 3 grams)

· Hydrochloric acid (20ml)

· Water (250)

· Goggles

· Weighing Scales.

Diagram Of Equipment Used.

Method

First of all I am going to test the rate of reactivity of the calcium carbonate (marble chips) at room temperature (25°c, this is because it was a heated room and the acid had been in their all day). I measured 3grams of marble chips and added them into a conical flask and 20ml of hydrochloric acid into a measuring cylinder. I added the acid into the conical flask with the marble chips and started the stop clock away. After 10 seconds and every 10 seconds I measured the amount of gas in the syringe until 70 seconds had gone by at which point I will measure the temperature of the hydrochloric acid. After each time I will throw away the marble chips because they cannot be used again as some reactant will have been used up. To get the best possible results I am going to test it 3 separate times to enable me to judge the amounts of gas produced fairly and decide if they are correct. After doing it 3 try's I will continue until the temperature reaches 60°c, on each of these temperatures I will use a Bunsen burner, I will put the hydrochloric acid into a boiling tube and place the boiling tube into a glass beaker filled with water used as a water bath to the acid to each separate temperatures. By heating the acid to this high temperature it would show me more accurately the results of how the speed changes by a rise in the temperature and if the start temperature has any effect on the finishing temperature.

Diagram of the experiment

On the following pages are my results

My results

Time of measurement (in secs)

25°c 10 20 30 40 50 60 70

Try 1

Try 2

Try 3

Average

Start Temperature- 25°

Finish Temperature- 44°

Change in Temperature-19°

Time of measurement (in secs)

25°c 10 20 30 40 50 60 70

Try 1

Try 2

Try 3

Average

Start Temperature-40°

Finish Temperature-67°

Change in Temperature-27°

Time of measurement (in secs)

25°c 10 20 30 40 50 60 70

Try 1

Try 2

Try 3

Average

Start Temperature-50°

Finish Temperature-81°

Change in Temperature-31°

Time of measurement (in secs)

25°c 10 20 30 40 50 60 70

Try 1

Try 2

Try 3

Average

Start Temperature-60°

Finish Temperature-86°

Change in Temperature-26°

Analysis of Results

On these tables of results I have used 4 separate tables to make the data understandable. To work out the average I added them up and divided by however many there were, which was 3. I have worked out the average because then the results will be judged properly and will be easier to b added into a graph to compare between each temperature. Underneath the tables I have added the start and finish temperatures to see clearly how much they differ, either increase or decrease. I will hope to prove that the temperature rises as the gas is release because the products are more stable than reactants and heat is given out. I have added the change in temperature, which I would also compare to notice easily any differences between each temperature. On the following pages are some graphs showing the rates at each temperature. On each graph of the different temperatures I have displayed all my 3 results to show how they are similar to each other by following the same rising pattern. Then on my final graph I have just used the averages, which makes it easier and clearer to compare the quantities of gas for each temperature. As I have only gone up to 60°, from these results I am going to predict the temperature for 70°, here is a table showing my estimated results;

Time of measurement (in secs)

70°c 10 20 30 40 50 60 70

32 51 68 85 98 109 112

Start Temperature-70°

Finish Temperature-95°

Change in temperature-25

Conclusion

In this experiment my aim was to find out what changes the rate of the Calcium Carbonate reacting with the Hydrochloric acid which I managed to succeed in doing so. I recorded the rates of the different temperatures effects. My prediction matched and concluded with my results, as you can tell from the graphs I have proved that the higher temperature the faster the marble chips react and produce a larger quantity of gas because of the heat giving amounts of energy (depending on the temperature). I noticed that during the experiment the amount of gas it was producing would slow down, this is because the activation energy which it had been given at the start gave it a 'boost' and at this point it would have been the fastest, until it had worn off which would be in the middle. The particles of acid and Calcium Carbonate react and give the acid energy to move about and collide with the CaCo3.

In the graphs, I saw definite patterns; they all have a positive correlation which shows that they are have the same trend. The graphs are an easier way to prove the same effects as the tables, this way it clearly shows that the higher the temperature the larger amount of carbon dioxide it produces.

Evaluation

The experiment I think went very well and I managed to get all the information I needed which I am very pleased about. At first I was aiming to raise the temperature up to 70° but it was producing a faster amount of gas which made it difficult for me to record, because it would be above the actual measurements on the syringe, so I only went up to 60°, although I still predicted the results using my original results.

The amounts of gas are not actually spot on accurate because I would have needed more time to prepare another experiment, making absolute certain all the fair testing was kept to a extremely high standard and the syringes measurements must be more accurate to read off to get the actual amount of that time and temperature, for example it needs to be to a more finer scale to improve accuracy but then again it would still cause difficulty to read because of the speed the reaction happens. The graphs and tables still show however the effects I wanted because the rise in the amount of gas as the temperature rises looks correct, I can still predict another set of experiments from them for other temperatures by using the pattern in them because all the information necessary was there which I needed to make a valuable reading.

The graphs proved to me my predictions were correct, as I didn't get any anomalous results, apart from the final graph when all the temperatures were put together. This final graph shows clearly that 25° and 40° were producing different amounts of gas than expected, The 25° was producing more gas than 40°, and this is unusual because the highest temperature should produce more.

At the beginning of the experiment I decided that it might be interesting to see if the temperature at the start changes from the finish temperature, I was interested to see if anything did change, so I thought for quite a while by using my own knowledge and wrote down what my theory was in my prediction. I was very pleased when I discovered that my theory was correct.