HCl acid is a strong acid, because it ionises almost completely when it dissolves in water. It releases hydrogen ions and gives it to water molecules:
HCl (aq) + H2O (l) H+(aq) + Cl-(aq)
The solution formed when the HCl acid dissolves in water contains a high concentration of H+(aq) ions. This means that it is a strong acid, as the acid breaks up into ions (ionises) almost completely into H+(aq) and Cl- (aq) ions.
The Ka (dissociation constant) for this example of HCl that we are using is 107 mol dm-3 because the HCl consists mainly of ions (H+), therefore it is a stronger acid than water for example, where it consists mainly of molecules, Ka also reflects the extent of the protanation of the water molecules. The acid is nearly fully dissociated, but no acid will ever completely and totally dissociate into ions, as even strong acids will not dissociate completely at high concentrations, some of the hydrogen will still remain bound to the chlorine.
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As you can see from the above formulae it shows that how an acid can be weak and strong, for example, the acid is weak if its Ka is less than 10-2 and its position of the equilibrium is mainly to the left. Where it is mainly molecules, e.g. H2O (l) and it shows a weak tendency to protonate the water molecules. While a strong acid like, HCl has a value of Ka more than 102 and its position of the equilibrium mainly is to the right. Where it is mainly ions e.g. H3O+(aq) and it shows a strong tendency to protonate the water molecules. And as you can see the position of the equilibrium system for the HCl is mainly to the right.
So to summarise, if the concentration of the acid is doubled, the rate of the reaction will be doubled, as there are twice as many reactant particles
(H+(aq) ions) in any given volume. So there will be twice as many collisions between the carbonate ions and the H+(aq) ions in a given time. Therefore, there will be twice as many effective collisions in a given time as there will be twice the number of particles with energy ≥Ea (activation energy needed to make the reaction). Therefore, we can monitor it because it will give out twice as many products. The average rate is measured by finding the time taken for the production of a given volume change for each concentration. Since:
Rate = Measured change
Time
Rate is proportional to 1 1
Time
Therefore, it is possible to plot rate against concentration. Below is a graph of a doubled concentration in a chemical reaction, with an original concentration:
Preliminary experiments
To decide on the values of the variables, I have done preliminary experiments, exploring the amount of calcium carbonate and the range of acid concentrations and what to use, granules, or powder. In addition, we were to refine our technique of getting the results and try different experiments. This experiment is important as we can know the correct amount of calcium carbonate so that the experiment would not be too quick to time, and not too slow either.
Technique 1-Gas syringe
Equipment:
-A 100cm3 gas syringe
-A 100cm3 conical flask
-A clamp
-A stand
-Rubber tubing
-Calcium carbonate granules
-Hydrochloric acid (maximum concentration=2 mol dm-3)
-A 100 cm3 measuring cylinder
-Stop watch (time measured to nearest second)
Method
I have used the gas syringe experiment; I timed how long it would take for the product of the experiment, (to nearest second) (Carbon dioxide) to fill 100cm3 of the gas syringe using different masses of calcium carbonate. Which I weighed (using an electronic balance to get a fairly accurate reading, to 2 decimal places), and different concentrations of hydrochloric acid. Which I diluted, using a pre-set percentage, e.g. 20%acid-80% water. I reacted both of the reactants in the conical flask, and putting the stopper on it, where the carbon dioxide then travelled through the rubber tubing that was linking from the flask to the syringe. My results are shown below:
From this I decided that the best mass to use is 2.00 grams of granules, this was because at 2.50 gm the reaction took place at a reasonable to quick rate. It was fast enough to get a wide range of results, but anything faster would make the experiment hard to record as the syringe would be filled too quickly; therefore I decided to use 2.00gm as at 2.50 gm it was getting a bit too fast for the 2 molars concentration. Also the range of concentrations I conclude as thus, 2 molars is the maximum concentration therefore it will be my upper limit and using water to dilute it to 20% acid-80% water is enough for this experiment, as otherwise it will be too dilute and the experiment will take too long to get a number of results.
- This preliminary experiment also proves that my prediction is correct, at a higher concentration, the rate of reaction is faster, i.e. for 7.50 gm at 2 molars it takes 8 seconds, but at 0.4 molars it takes 83 seconds.
The values of the other variables are:
Problems
- There is lag of time between the experiment happening, and timing it, as I have to put the Calcium carbonate into the acid, then time it, then put the stopper in.
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Some of the CO2 will have escaped by that time, therefore, not an accurate experiment.
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Sometimes the syringe does not move, because the stopper has been stuck, because the calcium carbonate bits have stuck to the rim, therefore preventing the stopper from going in completely, therefore the CO2 escapes. (I have had 4 null results, because of this)
- At low pressures, the syringe tends to stick and not move.
- The angle of the syringe is important as then in a horizontal angle, the gas will be pushing a less heavy syringe as it is a few degrees upright. (Because of gravity)
6. The experiment, took far too long, especially, in low concentrations.
Answers
1+2. Put the CaCO3 in first, then measure out the acid into the measuring
cylinder, then hold the stopper in the left hand. Hold the stop clock in the
right with the cylinder in the right hand as well, I can then pour the acid
and time it at the same time and can quickly put on the stopper without
losing too much CO2.
3. Put the CaCO3 first, before the acid and use a paper funnel so that the
Calcium carbonate bit does not get stuck on the side. If any does stick, use
a tissue to wipe it clean, so that there is no impedance of the stopper.
4. To counter the problem wipe the inside of the syringe using tissue after
each experiment to relieve most of the stickiness and make sure all the
connections are tight, so no leakage is being done.
- Make sure the syringes are all at a horizontal angle, so they are all the
same (fairness)
- To balance the speed, the experiment, gives very precise and reliable
results.
-I chose the granules as the powder has some problems:
- It may react too fast
- Some powder might be lifted by bubbles so not every bit has reacted
The granules however are good as, they sink to the bottom so there is no question of about have they all reacted and they can be put into the flask easier, without sticking to the sides. However, the problem with the granules, are that they have a covering of calcium carbonate powder, on the outside, and that they are of an uneven shape and surface area.
Below is a drawing of the experiment:
Technique 2-Reaction time
Equipment:
-100cm3 beaker
-Hydrochloric acid (maximum concentration=2mol dm-3)
-Stop watch (time measured to nearest second)
-Calcium carbonate powder
Method
This is the other method, which I have tried out. I timed how long it took to completely react a set amount of calcium carbonate, which I weighed (using an electronic balance to get a fairly accurate reading, to 2 decimal places), in varied concentrations of HCl, which I diluted, using a pre-set percentage, e.g. 20%acid-80% water. I have used powder for this method, because, the meaning of this experiment, is that I can get many results quickly, and powder, reacts quickly indeed. However using granules slows the experiment down considerably, which goes against the principle of this experiment. (As this experiment produces many results in a short space of time) Below are the results:
From this preliminary experiment, I conclude as thus, the best amount of calcium carbonate to use, is 1.00 grams, this is because, it gives, a nice, quick experiment, but it is not too slow to do or too fast to time. The 2.00 grams experiments were getting a bit too slow. The varying concentrations for the experiment should not be below 20% (0.4 molars) concentration, as the experiment grinds to a halt, as it has done here, it would take far too long to complete it.
The values of the other variables are:
I have used, powder because, using granules, defeats the meaning of this type of technique (which, is to get a lot of results in a short space of time, in balance to its less precise and accurate results), as granules, takes up too much time. Also powder allows me the best chance to get the:
- same mass (can take away, add on small amounts of powder, to get precise results)
- constant surface area (they are about the same shape and size, while the granules, are different in shape and size)
Problems
1. The readings will not be very accurate as you will be looking at the experiment for a qualitative result and therefore there is a margin of error because you will have to make a judgement on whether the reaction has stopped or not.
2. The time lag between the putting in of the calcium carbonate powder and the start of the timing.
3. The powder may not stay in the solution, the bubbles may lift it, and therefore not every bit, will have reacted and therefore, will not give us an accurate result.
4. The powder may react too fast for us to time.
5. Using the “boat” carriers, there may be some residual, calcium carbonate powder left in the boat, when you pour the calcium carbonate in to the beaker, to react with the HCl.
6. There will be residuals of calcium carbonate, left in the boat, from the previous experiment, when you measure the new ones in on the boat on the balance, therefore getting more than the weight you see on the display.
Answer
1. To offset the balance of not very accurate results, this experiment can be done very quickly, therefore can be repeated a number of times, so that an average can be gotten, and so from this experiment a reasonably accurate result can be got. However, the experiment is not as accurate or precise as some of the other techniques I have discussed
2. There will be a lag for all the experiments, so it would not matter, you would just have to, try to leave the same lag for every experiment.
3. This is the major problem with this experiment (variables), but if we take the average, and do many results, then this variable would not matter as much.
4. The preliminary experiments are designed so that we will know the correct amounts of the reactants to use, so that the experiment would not be too fast or too slow.
5. Scrape the calcium carbonate onto a piece of paper, then the calcium
carbonate will not stick on to the paper, so you can pour all the calcium
carbonate into the beaker to react.
6. Make sure the measuring boats are clean, before use, and if not, clean
them before weighing the calcium carbonate, to remove the residuals, so
that they will not be a part of the experiment.
Below is a drawing of the experiment:
Technique 3-Change in mass
Equipment:
-Digital balance (reads to 2 decimal places)
-100 cm3 conical flask
-Cotton wool
-Hydrochloric acid (maximum concentration=2mol dm-3)
-Calcium carbonate granules
-Stop watch (time measured to nearest second)
Method
Put the flask containing the acid, granules on a piece of paper, and the cotton wool on to the balance, and turn on the balance (so it reads 0.00). This is the starting mass, we then put the calcium carbonate granules into the flask, and put the cotton wool on, we then start timing. We time at intervals of 10 seconds, and record the decreasing mass, the cotton wool is to stop the reactants, spitting out when reacting.
Problems
I did not do this experiment because there were not enough balances to go around. Therefore, I could not do the experiment.
Answer
Get some more balances so that we can use it for experiments.
Below is a drawing of the experiment:
Technique 4-Collection over water
Equipment:
-100cm3 conical flask
-Measuring cylinder
-Clamp
-Stand
-Container
-Delivery tube
-Stopwatch (time measured to nearest second)
-Hydrochloric acid (maximum concentration= 2 mol dm-3)
-Calcium carbonate granules
Method
Fill the container with water about half way up, fill the measuring cylinder with water, and then turn it upside down so that the container is standing in the tub still filled with water. Connect the delivery tube from the flask to underneath the measuring cylinder. Put the flask on the clamp so that we do not have to hold it, and then put CaCO3 granules in it. We then as soon as the acid is in, we put the stopper on and time the experiment. We record the amount of water at every 10-second interval and so we are able to work out how much CO2 has displaced the water.
Problem
- There is a small margin of error if there is a small displacement of the water, when trying to tip the measuring cylinder upside down.
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Some of the CO2 will dissolve in the water (as carbon dioxide is soluble) when the bubbles are going to the cylinder.
I did not do this technique because of time constraints.
Answer
1. Tip the cylinder under water inside the container filled with water, and so no displacement will occur.
2. Do the experiment once or twice, and it will saturate the water, and anyway the difference is very small between the unsaturated and saturated water.
Below is a drawing of the experiment:
Fairness
In all these different methods and techniques, all need to be done fairly. Below is a list of what could affect the rate of reaction and what I have done and will do to make it fairer:
-Size of the calcium carbonate -I have picked according to my eye, the roughly the same size of granules. (For powder, it does not matter as much, as they are roughly the same size.)
-Concentration of hydrochloric acid-it is taken from a bench solution of 2 mol dm –3 and then diluted if necessary, accurately according to the proportions.
-Volume of acid/water- I have used two 50 cm3 measuring cylinders to
measure out the acid and the water, I have measured it to the 1 cm3
markings as carefully as possible, before mixing it together in a 100 cm3
beaker. This was done to proportion, in accordance, with the concentration.
The total solution was 50 cm3.
-Mass of calcium carbonate-Measured on a digital balance, correct to 2 decimal places.
-Surface area of calcium carbonate -There might be some bits of calcium carbonate powder on the granules, therefore increasing the surface area; I have washed the granules in water to get rid of the powder and correcting it. (For powder, it does not matter as much, as they are roughly the same.)
-Temperature-Will be conducted at room temperatures, the temperature of the room is the same because there is a thermostat allowing it to be a certain amount of degrees, and the experiment will be conducted at the same distance away from the radiators.
-Light intensity-The light intensity has a very small affect on the experiment and so there will not be a big margin of error.
-After the experiment, there will be residue HCl acid in the flasks-I shall rinse it out with tap water. Although there is to be a certain amount of calcium in the water (from calcium hydrogen-carbonate), it is not that important, as 1) the experiment is done in a soft water area and 2) The difference will be negligible.
-The angle of the syringe in the gas collecting experiments has to be same in all the experiments. So that the force exerted by the gas will be the same for all the experiments (if the same variables apply) otherwise, one might find that because of gravity, in one experiment it runs smoothly and in the next, because of the angle, the syringe is not moving at all. Answer: make the syringe parallel to the desk, so there is fairness in all the experiments.
I have controlled these factors, because any one of them might give me an anomalous result, because these factors determine the rate of reaction.
Getting Results
In the investigation, I shall have two techniques. My main one, is the gas syringe collection of carbon dioxide, (Technique 1) as it gives very accurate and precise results and data.
Technique 1-Gas syringe
-A 100cm3 gas syringe-measured to the nearest cm3 as possible (markings up by 5cm3)
-A 100cm3 conical flask
-A clamp
-A stand
-Rubber tubing
-Calcium carbonate granules
-Hydrochloric acid (maximum concentration=2 mol dm-3)
-A 100 cm3 measuring cylinder-measure the substance to the nearest cm3
-Stop clock-measure the time to the nearest second
-Digital balance-2 decimal places
Method
I will be recording the volume of the product of the experiment, which I am measuring, (Carbon dioxide) at every 10 seconds as this is a suitable time interval for finding a measurable change to take place. I shall do the experiment as thus:
- I will make sure the stools are tucked in and my bags are away, I will need a pair of goggles and an apron.
- I shall get a white board and put it on my desk.
- I will get the stand and clamp.
- I will get the syringe, conical flask, the rubber tubing.
- I will get a beaker of HCl acid-100ml (2 molars)
- I shall get the calcium carbonate granules, which I will weigh (using an electronic balance to get a fairly accurate reading, to 2 decimal places) it will be on a measuring “boat.” (Making sure the scale is reset after the boat has being put on it) (I shall get 2 portions of Calcium carbonate as it reduces the time of travelling to and fro from the experiment), I shall use 2.00 grams of calcium carbonate granules for each experiment.
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I shall get a 50 cm3 measuring cylinder, with 1 cm3 markings, so that the measurement will be as accurate as possible.
- I shall get another beaker filled with water.
- This is so that I can dilute the acid into the wanted concentrations:
50ml acid- 0ml water (100% concentration)
40ml acid-10ml water (80 % concentration)
30ml acid-20ml water (60% concentration)
20ml acid-30ml water (40% concentration)
10ml acid-40ml water (20% concentration)
10. When diluting, I shall make sure that I put the acid into the water,
and stir, because, the acid’s density is bigger than the water’s, so it will sink to the bottom and it will heat the water up, otherwise if put in the other way the water will float on top of the acid, and will react violently, including spitting the contents out of the beaker.
11. I shall react both of the reactants in the conical flask, putting the calcium
carbonate in through a paper funnel so that the bits do not stick to the
side.
12. I shall time it accurately, I will be holding the watch in the same hand as the acid beaker where I will press it as soon as the acid reaches the calcium carbonate and close the stopper immediately.
- At measuring the volume, I will have a 2 second lee way because I will not be able to record it to the exact time.
- After the experiment, I will wash the flask out with water.
- And do the experiment again for accuracy.
The time scale for this experiment is 4 minutes as this will give me enough data to draw an accurate graph and would not wait too long to complete one experiment. This will also give me enough time to repeat the experiment 3 times for each concentration:
50ml acid- 0ml water- 2 molars (100% concentration)
40ml acid-10ml water-1.6 molars (80% concentration)
30ml acid-20ml water-1.2 molars (60% concentration)
20ml acid-30ml water-0.8 molars (40% concentration)
10ml acid-40ml water-0.4 molars (20% concentration)
Here is a rough table that I am going to use for recording my data:
/// Represents, the values in between the sets of data, I have left spaces, so that anomalous results can be rectified and redone if needed.
So in all I will be doing, 5 experiment, 3 times each, so resulting in 15 results. My range of data is 4 minutes; this is so that I will have enough time to finish other experiments, and not to stay too long on one experiment.
Here are the lessons that I have learned from the preliminary experiments for Technique 1:
Problems
- There is lag of time between the experiment happening, and timing it, as I
have to put the Calcium carbonate into the acid, then time it, then put the
stopper in.
-
Some of the CO2 will have escaped by that time, therefore, not an accurate experiment.
-
Sometimes the syringe does not move, because the stopper has been stuck, because the calcium carbonate bits have stuck to the rim, therefore preventing the stopper from going in completely, therefore the CO2 escapes. (I have had 4 null results, because of this)
- At low pressures, the syringe tends to stick and not move.
- The angle of the syringe is important as then in a horizontal angle, the gas will be pushing a less heavy syringe as it is a few degrees upright. (Because of gravity)
6. The experiment, took far too long, especially, in low concentrations.
Answers
1+2. Put the CaCO3 in first, then measure out the acid into the measuring
cylinder then hold the stopper in the left hand. Hold the stop clock in the
right with the cylinder in the right hand as well, I can then pour the acid
and time it at the same time and can quickly put on the stopper without
losing too much CO2.
-
Put the CaCO3 first, before the acid and use a paper funnel so that the
Calcium carbonate bit does not get stuck on the side. If any does stick,
use a tissue to wipe it clean, so that there is no impedance of the stopper.
- To counter the problem wipe the inside of the syringe using tissue after
each experiment to relieve most of the stickiness and make sure all the
connections are tight, so no leakage is being done.
- Make sure the syringes are all at a horizontal angle, so they are all the
same (fairness)
- To balance the speed, the experiment, gives very precise and reliable
results.
However if the experiment, proceeds too slow, an alternative backup Technique will be used. It will be Technique 2 (Time for reaction to complete)
Technique 2-Reaction time
Equipment:
-100cm3 beaker
-Hydrochloric acid (maximum concentration=2mol dm-3)
-Stop clock
-Calcium carbonate powder
Method
I will measure how long it takes for the reaction between varying concentrations of HCl acid and a set amount of calcium carbonate powder, (1.00 grams). I shall measure the reaction to the nearest second. I shall do the experiment as thus:
1. I will make sure the stools are tucked in and my bags are away, I will need a pair of goggles and an apron.
- I shall get a white board and put it on my desk.
-
I will get a 100cm3 beaker.
- I will get a beaker of HCl acid-100ml (2 molars)
- I shall get the calcium carbonate powder, which I will weigh (using an electronic balance to get a fairly accurate reading, to 2 decimal places) it will be on a measuring “boat.” (Making sure the scale is reset after the boat has being put on it) (I shall get 2 portions of Calcium carbonate as it reduces the time of travelling to and fro from the experiment), I shall use 1.00 grams of calcium carbonate powder for each experiment.
-
I shall get a 50 cm3 measuring cylinder, with 1 cm3 markings, so that the measurement will be as accurate as possible.
- I shall get another beaker filled with water.
- This is so that I can dilute the acid into the wanted concentrations:
50ml acid- 0ml water (100% concentration)
45ml acid- 5ml water (90% concentration)
40ml acid-10ml water (80 % concentration)
35ml acid-15ml water (70% concentration)
30ml acid-20ml water (60% concentration)
25ml acid-25ml water (50% concentration)
20ml acid-30ml water (40% concentration)
9. When diluting, I shall make sure that I put the acid into the water,
and stir, because, the acid’s density is bigger than the water’s, so it will sink to the bottom and it will heat the water up, otherwise if put in the other way the water will float on top of the acid, and will react violently, including spitting the contents out of the beaker.
10. After the experiment, I will wash the flask out with water.
11. And do the experiment again for accuracy.
The time scale for this experiment is 4 minutes as this will give me enough data to draw an accurate graph and would not wait too long to complete one experiment. This will also give me enough time to repeat the experiment 3 times for each concentration (I have used more concentrations variance as, the technique produces quick experiments, so I have time to do a variance of concentration):
50ml acid- 0ml water- 2 molars (100% concentration)
45ml acid- 5ml water- 1.8 molars (90% concentration)
40ml acid-10ml water-1.6 molars (80 % concentration)
35ml acid-15ml water- 1.4 molars (70% concentration)
30ml acid-20ml water- 1.2 molars (60% concentration)
25ml acid-25ml water- 1 molars (50% concentration)
20ml acid-30ml water -0.8 molars (40% concentration)
Here is a rough table that I am going to use for recording my data:
/// Represents, the values in between the sets of data, I have left spaces, so that anomalous results can be rectified and redone if needed.
So in all I will be doing, 7 experiment, 3 times each, so resulting in 35 results. My range of data is for 4 minutes; this is so that I will have enough time to finish other experiments, and not to stay too long on one experiment.
Here are the lessons that I have learned from the preliminary experiments for Technique 2:
Problems
1. The readings will not be very accurate as you will be looking at the experiment for a qualitative result and therefore there is a margin of error because you will have to make a judgement on whether the reaction has stopped or not.
2. The time lag between the putting in of the calcium carbonate powder and the start of the timing.
3. The powder may not stay in the solution, the bubbles may lift it, and therefore not every bit, will have reacted and therefore, will not give us an accurate result.
4. The powder may react too fast for us to time.
5. Using the “boat” carriers, there may be some residual, calcium carbonate powder left in the boat, when you pour the calcium carbonate in to the beaker, to react with the HCl.
6. There will be residuals of calcium carbonate, left in the boat, from the previous experiment, when you measure the new ones in on the boat on the balance, therefore getting more than the weight you see on the display.
Answer
1. To offset the balance of not very accurate results, this experiment can be done very quickly, therefore can be repeated a number of times, so that an average can be gotten, and so from this experiment a reasonably accurate result can be got. However, the experiment is not as accurate or precise as some of the other techniques I have discussed
2. There will be a lag for all the experiments, so it would not matter, you would just have to, try to leave the same lag for every experiment.
3. This is the major problem with this experiment (variables), but if we take the average, and do many results, then this variable would not matter as much.
4. The preliminary experiments are designed so that we will know the correct amounts of the reactants to use, so that the experiment would not be too fast or too slow.
5. Scrape the calcium carbonate onto a piece of paper, then the calcium
carbonate will not stick on to the paper, so you can pour all the calcium
carbonate into the beaker to react.
6. Make sure the measuring boats are clean, before use, and if not, clean
them before weighing the calcium carbonate, to remove the residuals, so
that they will not be a part of the experiment.
FACTORS
However there will be some factors that will stop me from doing the experiment accurately. And they are important factors, which I have to bear in mind while I do my investigation.
- I said that temperature, was an important factor, but said that it was OK because the room temperature would be roughly the same for all the experiments because of the thermostat, and the same position of the experiment away from the radiators. However, in fact, there is an important issue, to consider, as when I pour the acid into the water, and stir it then add the calcium carbonate. An reaction has already taken place:
HCl (aq) + H2O (l) H3O+(aq) + Cl-(aq) (Heat is given out.)
Heat is given out as new bonds have been formed, (H3O+(aq) ), this is an exothermic reaction. Therefore, the temperature of the solution of acid/water is heated up slightly, this adds energy to the reaction, affecting how quickly the particles move, therefore increasing its rate of reaction, so in fact, at the earlier mixings, of 45ml acid – 5ml water, 40ml acid – 10ml water. There would be a more prominent temperature rise, as there is more acid than water, so the rise in temperature of the water would be grater as the heating would apply to a smaller amount of water, resulting in a higher temperature rise, when that proportion of acid and the water are mixed together. Therefore, when the calcium carbonate is added to these proportions of acid/water solution, there would be a higher rate of reaction because a higher temperature adds energy to the reaction, affecting how quickly the particles move, therefore increasing its rate of reaction. However for the lower amounts of acid added onto a higher amount of water, there would be a small increase in temperature, and not affect the rate of reaction too much. And to conclude, for a higher amount of acid added onto a smaller amount of water, the rise in temperature is more prominent and will affect the rate of reaction, while the lower amounts of added acid would not affect the rate of reaction to the same degree.
-
The water that comes out from the tap, which is used to dilute the acid, into the acid/water proportion solution, is not in the same temperature as the room temperature. It comes from the cold-water tap and therefore on some days the water is colder than on others when used for the experiment. As the weather outside controls the temperature inside the plumbing. Therefore, I am forced to conclude, that in the experiment the water temperature will vary 1-3 degrees Celsius from each other day’s experimentations. And so, a higher temperature adds energy to the reaction, and affecting how quickly the particles move, therefore increasing its rate of reaction a lower temperature will also affect how slowly the particles move, and slow the rate of reaction down. Therefore, in linking with the above theory of the acid-water reaction, temperature will play an important part in the experiment as well.
-
All the timings are all rounded up or down to the nearest second. Rounded up can only be possible if the last two digits of the milliseconds are 50 or above and anything below is rounded down. This does not give truly accurate results, but for the sake of ease, and processing the results, it is better for the results to be in whole integers.
Bibliography
- Year 4 rates of reaction sheet
- GCSE Chemistry-Bell and Hyman
- Chemistry-Blackie
- Chemistry for First Examinations-R.Wilford
- Progress with Chemistry 2-Brian Stewart
- A-level Chemistry-E.N.Ramsden
-
GCSE Chemistry-Bob McDuell
- Advancing Chemistry-Michael Lewis/Guy Walker
- Mastering Chemistry-P.Critchlow
- Nuffield Advanced Science-Topics 12-18
- General Chemistry-David Nicholls
- AS Chemistry-Andrew Hunt
- Collins Chemistry-Geoffrey Hallas
- GCSE Science-Andrew Maczek
- Chemistry-J A Hunt/A Sykes
- Key Science Chemistry-Eileen Ramsden
- Class notes
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Page 4 “Particle collision” picture-Philip Xiu©
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Various experimental pictures-Philip Xiu©
