Investigating making Epsom salts by varying the rates of reaction.

Krina Patel Chemistry Coursework. - -

Epsom Salts Coursework

Aim: investigating making Epsom salts by varying the rates of reaction.

Research: Reaction with Dilute Acid: Potassium, sodium, lithium and calcium
all react violently with dilute H2SO4(aq) and dilute HCl (aq).The reaction is similar to the reaction with water, forming the metal salt (either sulphate or chloride) plus H2(g). Magnesium, aluminum, zinc, iron, tin and lead react safely with dilute acid,
magnesium is the fastest and lead is the slowest of the six.

Magnesium + sulphuric acid magnesium sulphate + hydrogen.
Mg(s) + H2SO4(aq) MgSO4(aq) + H2(g)

There are many different uses for Epsom salts (magnesium Sulphate) When magnesium sulphate is absorbed through the skin, such as in a bath, it draws toxins from the body, sedates the nervous system, reduces swelling, relaxes muscles, is a natural emollient, exfoliate, and much more. Epsom salts can be used for many things such as:

Relaxing and Sedative Baths
Face Cleaner
To make Homemade Skin Masks
To soak feet
To exfoliate skin
Remove Excess Oil from Hair
Hairspray
Hair Volumizer
Soak Sprains and Bruises
And to remove splinters

This piece of information was obtained from ------care2.com.

Epsom salts is the name originally given to hydrated magnesium sulphate, MgSO4.7H20 .Millions of people all over the world have asked for Epsom salts, and used it with recognisable effect, without knowing anything about Epsom. The reasons for the efficacious action of Epsom salts were not known until a long time after its discovery, and magnesium as an element was not discovered until nearly a century later.

This piece of information was obtained from

The bonds between magnesium and sulphate has a lot to do with the rates of reaction and how different variables affect the substances so here is some information about the rates of reaction:

Some chemical reactions are fast others are slow. The reactions go at different speeds or rates and this is often dependant on the variable or variables that are used on the metal. There are various rates that we are able to vary such as:

The temperature – by using temperature as a variable you are able to control the reactions. If you increase the temperature by 10 ° then you would expect the chemical reactions to work at twice the rate because raising the temperature makes the particles in the sulphuric acid to move twice as fast which would increase the number of times that the particles collide with each other. If the temperature is reduced then this would slow down the reaction process as this would mean that the particles are less energetic as they are not being heated up so that they collide more often this would result to less reaction being given off in this case less hydrogen would be produced.
The concentration – the concentration affects the rate of reaction, as the more concentrated the solution is the more stronger the solution is which would mean that the substance i.e. sulphuric acid is more concentrated relieving more power which would mean that the reaction would be stronger and greater than a weaker solution. Increasing the concentration would also mean that there would be more particles per dm³, and the more particles there are the more they would collide per second which would release a greater reaction. However decreasing the concentration will lead to the opposite effect of that of a higher concentration, there would be less particles per dm³ which would result in a less reactant solution. Also the more concentrated the solution gets or the less used of it would mean that the solution gets weaker and less able to produce a energetic reaction.
Increasing the surface area – if the surface area is increased then in theory this would just mean that there would be a greater amount of this substance as there is more space for the substance, this would mean an increase in acid which would mean a greater reaction if the surface area is decreased then the reaction would be limited as thee is less solution to react the metal with.
Increasing pressure – if gases are being reacted with then increasing the pressure of this gas would mean that there would be more particles per dm³. This again reflects back onto the collision theory about the more particles there are the more will collide per second which would mean that the rate of reaction would increase.
A catalyst - A catalyst (strictly speaking) will change the rate of reaction.
A catalyst can make a reaction go faster or slower. In practice, a catalyst is mainly used to make a reaction go faster a catalyst works by providing a convenient surface for the reaction to occur.
The reacting particles gather on the catalyst surface and
1) more frequently with each other,
2) more of the collisions result in a reaction between particles because the catalyst can lower the for the reaction. A catalyst is often used as a powder, so that it has a bigger surface area per gram

I have now discussed all the variables that I am able to use in my experiment of making Epsom salts and how different actors would affect this process. I am now going to talk about the collision theory as the collision theory is the main theory behind all these variables:

The collision theory

The collision theory is basically when particles react to produce a reaction. Reactions occur when the particles are facing the correct direction and when there is enough energy present to make the reaction. The more collisions between the particles and the harder they hit each other means the higher the reaction rate. There are many ways in which to increase the reaction rate for example to increase the temperature. Below is a diagram of how the particles will look if the temperature is cold and how the particles move when the temperature is hot.

As you can see where the temperature is colder the particles are less energetic and not that close together which means that it takes a longer time for them to collide and with a decrease amount of force applied as they have less energy inside them to give out. Whilst where there is more heat applied the particles have more energy leading to frequent and harder collisions between the particles which means that they can release more energy and the reaction process would occur at a faster rate.

The other aspect that affects the collision rates is the concentration (or pressure), if the solution is more concentrated it means that there are more particles of reactants knocking about between the water molecules which makes the collisions between the important particles frequent and likely to occur. The diagram below shows you this:

As you can see the high concentration area has more particles which means that they \are more likely to collide frequently releasing more energy, whilst the low concentration has less particles meaning it would take longer for the particles to reach each other to collide. In a gas the increasing of pressure means that more particles are present which means that they are squashed up, again this relates to the more particles the more the greater the chances are of collision.

Another aspect that affects collision rates is catalysts. Catalysts increased the number of collisions. A catalyst works by giving the reacting particles a surface to stick to where they can bump into each other. The greater amount of catalysts used the more elements the particles have to stick onto increasing the rate of collision.

The diagram below explains what I am trying to say:

In theory not all collisions bring about a chemical change, meaning it does not necessary work. A collision may be affective in making a chemical. This was the collision theory. I am now going to start writing up my investigation. This investigation is basically to find out how in the process of making Epsom salts (magnesium sulphate MgSo4) different variables would affect it, in my case it would be how the levels of hydrogen gas would be affected as I am going to be varying the concentration of sulphuric acid. I have decided to choose to vary the concentration because after looking at the variables that I am able to differ I thought that varying the concentration would be the safest option. Below I have listed the risk assessments of all the elements that I am going to use in this investigation:

Sulphuric acid – is very corrosive. It can cause server burns. The solution is equal to or stronger than 1.5m. Fuming sulphuric acid (0leum) is more hazardous as the fumes of sulphuric acid are very dangerous to the human system. This is not recommended for use in schools.

Suphuric acid is also dangerous with water, hydrochloric acid, chlorides, hydrogen chloride, phosphorous, sodium, potassium and many other metals as dangerous reaction can take place.

If swallowed: you should wash out mouth and drink glasses of water. Do not induce vomit and then seek medical help.

If splashed in eye: care should be ...

This is a preview of the whole essay

Sulphuric acid – is very corrosive. It can cause server burns. The solution is equal to or stronger than 1.5m. Fuming sulphuric acid (0leum) is more hazardous as the fumes of sulphuric acid are very dangerous to the human system. This is not recommended for use in schools.

Suphuric acid is also dangerous with water, hydrochloric acid, chlorides, hydrogen chloride, phosphorous, sodium, potassium and many other metals as dangerous reaction can take place.

If swallowed: you should wash out mouth and drink glasses of water. Do not induce vomit and then seek medical help.

If splashed in eye: care should be taken when handling this acid as it is a very corrosive solution. If in contact with eye then make sure you flood the eye with tap water for 10 minutes and then seek medical attention.

If splashed on skin or clothes: if the acid spills on your skin then wipe as much of the acid off with a dry cloth and then drench affected area with large excess water. If skin starts to blisters then seek medical attention immediately. If the acid is spilt on clothing then remove contaminated clothing and pay attention to the skin if solution has seeped through then follow the methods of above.

Magnesium

Magnesium sulphate

Hydrogen gas

So by looking at all the risk assessments of the above elements I think it is wise not to use the temperature as the variable because if sulphuric acid is heated up then it will create fumes which is not ideal to do as it is very dangerous to us and it is not practical to heat it up in a school laboratory it would be alright if we were in a professional laboratory with the correct high-tech equipment to protect ourselves and to conduct the experiment properly. It is also not ideal to use temperature as if acids are heated up they usually splash out, and due to the risks of the sulphuric acid has on the skin it would not be ideal to heat it up because if we do heat it up then we are literally looking at casualties. Another reason not to use temperature is that both magnesium and hydrogen are highly flammable and it is not a good idea t have them around naked flames after knowing this. I could vary the surface area, so this would basically mean to use different amounts of magnesium metal to see what the affect of having more or less metal has to do with the amount of hydrogen produced, but the reason that I am not going to do this is because it would not be a fair test as the amount that I will increase or decrease would not be able to be constant. Also it is not qualitied, I will not be able to get qualited results by using the surface area which means that when I draw my graphs I will not be able to draw line graphs which I need for I will only be able to draw bar charts due to the type of results that I would receive.

I can not increase the pressure because you are only able to increase the pressure of a gas and as I am not using a gas element I the practical I can not vary this. I am producing a gas. I can also vary the catalyst but this would be the same as the surface area or varying the mass of magnesium. As if I use the catalyst all I will be doing is increasing the amount of magnesium used each time this is the same as the surface area because if I choose to vary the surface area all I was going to do was again increase the amount of magnesium used which would results in more surface for the articles but as this does not give be qualified results I am not doing it so this same principle affects me if I were to vary the catalyst so there is no point because then there would be no point of me doing my experiment if I am not able to plot my results down properly.

So my overall choice that I have made is going to be to vary the concentration, although it is not straight forward to choose the concentration as my variable because when sulphuric acid is diluted it produces a very vigorous reaction and this is what I am going to have to do if I want to change the concentration. I am going to have to add water to dilute the concentration each time so that I get a decrease in the levels of concentrations that I use. It is possible to work with water and the sulphuric acid, but lots of precautions would need to be taken and what will need to be done is that the acid will need to be added to the cold water slowly, and it should always be that way around it should never be to add the cold water to the sulpuric acid. It is also possible to vary the concentration because a bung will be placed over the beaker which will prevent any splashes to come out of it so all the reaction will be able to stay inside the beaker and not able to come in contact with us.

Prediction:

What I predict is that the more concentrated the solution is the more reaction would take place which would mean that more hydrogen would be produced and as the concentration levels decrease the reactions would become weaker and less hydrogen would be produced. I base this prediction on the collision theory, as the stronger the solution means that there would be more particles per dm³,which would mean that they would be able to collide with each other more often than when the solution is a lot weaker. The weak solution would mean that it would be a lot harder for the important particles to collide with each other as there would also be water particles in the solution rather than pure So4.i also think that as time goes on the reaction would start to increase in producing volume of hydrogen as the magnesium and the sulphuric acid would have had more time to react.

Preliminary testing:

I will be conducting a preliminary test so that I am able to make sure that everything goes well and that I receive good enough results when varying the concentration.

Apparatus that will be used when conducting this experiment:

Conical flask
Delivery tube
Rubber bung
Wooden blocks
Water bath
Measuring tube

In this experiment I will be measuring the reaction every 30 seconds up to 210 seconds. I have chosen to record the results after each 30 seconds because I feel that it is the correct interval to measure the reaction at. By going up to 210 seconds I will be able to analyse what happens to the reaction as time goes on so does the hydrogen produced increase or decrease in levels also going up to 210 seconds provides me with a set of 7 results per concentration which would enable me to get a good average and it is a good amount of data to be able to analyse.

I have chosen the concentrations of 100%, 9:1, 8:2, 7:3. The way in which the concentrations were worked out is that we are allowed to have 1x molar of sulphuric acid which is basically 10cm of acid = 100%. So to work out the concentrations we wanted all we did is what ever % we wanted we divided it by 100. so we did 90%, 80% and 70% this gave me 9, 8 and 7 as the concentration of sulphuric acid then all I did was make the percentages to 100 so 9 and 1 is 10 therefore it is 100% and so on, the numbers 1, 2 and 3 is the cm of water that I am going to used to dilute the sulphuric acid.

Safety precautions:

During this experiment I will need to take precautions, precautions on safety and accuracy. my safety precautions are that I need to wear safety goggles at all times this is because we are using sulphuric acid and it is harmful to the eye so to prevent it entering the eye goggles will reduce the chances . Alertness needs to be maintained by everyone this is because if you are not listening or paying attention to one and other than the chances of having an accident increases. Precautions of spillages should be taken because the acid is harmful it would be advisable not to spill it on the benches because then it can get in contact with skin or in eyes if people do not know it is there it can be passed along anywhere . Precautions should also be taken when moving around the room; you should not travel across the lab with acid in your hand if possible because if you trip then it would be dangerous to not only the person carrying the acid but to others. Bags should be put on the side so nobody falls over them, stools should be tucked under. You should stand up when conducting the experiment as it is easier to see and to do things.

Precautions that need to be taken with accuracy: would be to make sure that the acid is measured out correctly, to the nearest centimeter as possible of course it can not be absolutely perfect as it is bound to be 1cm +/-. Also precautions will need to be taken to remember to change the water in the glass tube every time the results are recorded for a set of concentrations as then it would not be a fair test. We will also need to remember to wash out the conical flask each time we are finished with a concentration as then it would not be a fair test if pieces of magnesium are left inside or some acid is left inside. When weighing the magnesium we should always have the weight precise as this is the one element that we are able to have precise because the weighing scales are accurate and we can add or subtract even brake the pieces to make sure that they weigh exactly what we want them to. Other precautions of accuracy would be to make sure when timing the reaction the results are read off at the time that they are meant to obviously like when measuring the concentrations it is hard to read off the results exactly on time as time does not stop and wait for you, but they should be read off as near to the time as possible and the results read off should also be as accurate as possible +/- a cm should not make a difference but major mishaps would make a difference to the overall results.

During this experiment we should also take in consideration the element of fair testing:

The fair testing that should be taken into consideration is:

The conical flask should be washed thoroughly after each test to ensure no pieces of magnesium or sulphuric acid exists inside.
The amount of magnesium should be kept constant.
The time that has been set should not be changed during the experiment; we should stick to one timing scheme and not change it.
The water in the glass tube should always be filled right to the top which is over 10cm when put upside down this is so that if any water spills during the process of turning the tube upside down it will not pass the 1cm mark.
Water in the plastic measuring cylinder should also be changed each time to ensure fair testing.

Method:

Firstly what we did was to collect all the equipment need list of the equipment is listed above. Then we set it up like this:

Diagram:

What we had to do is first we filled the tub with water and placed it to one side of the bench, whilst this was going on someone was setting up the conical flask and the delivery tube. What we had to do for this is collect two wooden blocks and place them on the bench first and then place the conical flask on top of this, this is because otherwise the delivery tube would not be able to reach the bottom of the glass burette because it would have been to low. We then has to get two little measuring cylinders and start to measure out the concentrations for the first one we were using 100% sulphuric acid so we did not need to measure out any water, so we measured out 10cm of the acid and then went to weighed the magnesium turnings out. We decided to used 0.2g for the preliminary testing and see what happens from there. So when we had all the little elements ready we had to fill the plastic measuring cylinder up with water and carefully place it upside down in the tub full of water upside down, being careful that only a limited amount of water falls out as little as possible sp that we can make it a fair test. The delivery tube had to be placed under the measuring cylinder as you can see in the diagram. Once everything is ready then add the sulphuric acid and the magnesium together, the rubber bung should then be placed on top this should be a fast process as once the acid comes in contact with the magnesium the reaction starts, so the stopwatch has to be placed on as soon as possible so that the reaction can stay inside the conical flask and so that oxygen is not able to come in contact with the magnesium other wise there would be two reactions happening. Once the reaction has started to take place one person must always hold the glass burette as it will not stand up on its own and the other person must keep a record on the time, after every 30 seconds we recorded the amount that the water had decreased by and so no until 210 seconds.

This process has to repeat three more times because overall four different concentrations have to be used and at the end of each concentration what we did was we made sure we washed out the conical flask and filled up the water in the glass burette again.

Below are the results of the preliminary testing:

As you can see from the results table above the column of 7:3 is not filled up and this is due to timing we did not have enough time in the lesson to complete the full test so we had to leave it, what this informs us is that we either have to reduce the time intervals because of our intervals being 30 seconds it is taking much longer than any body else’s, or we have to work at a faster rate. The other reason to why we did not have time to do the last experiment was due to we forgot on several occasions to wash out the conical flask and we often remembered after we added the acid inside and the magnesium, so we had to take it out spill the acid and the magnesium turnings and start all over again because it is not called a fair test if we do not wash the flask out. Other problems that we faced which delayed out time was to put the burette upside down in the water bath, this is because everytime we tried to do this the water contents inside the burette would spill out so we would have to refill the water and try again.

From the preliminary testing what I can evaluate is that for some reason there does not seem to be that much difference between the amount of hydrogen produced depending on the amount of concentration .The results seem to be fairly close together and stay in the range of 20 – 60cm. What I thought would happen is that there would be a drastic change in the results but then if I think about it there would not be a drastic change because we have not used drastic changes in the concentrations so we would not see the clear effects. If I wanted to see big changes in the hydrogen produced then I would have had to have a variety of ranges in the concentration and change is drastically e.g. from 100% to 50%. We ended up doing the experiment with the same concentrations that we used in our preliminary testing this is because we did not mark this problem before, we did not pay attention to the results that much and that was a mistake. I only realised this piece of information when I was analyzing the results and this was too late.

The next time when we conducted our proper experiments what happened is that although we used the same magnesium substance magnesium turnings, what was going on was that the rate of the reaction was happening too quickly so in the space of 30 seconds 40cm of water would have been lost, and we were finding that before 210 seconds all the water was finished ,we did not believe it at first so we started up another experiment along side one and it was true the reaction for some reason was really fast and it had defiantly increased in speed since the pilot testing. We then had to change the type of magnesium we were using to magnesium ribbon and we decreased the amount that we were using as well from 0.2g we decided to use 0.1 g so that incase the mass of the magnesium was the cause of the fast reaction, by reducing the weight maybe the reaction will slow down. After we changed the magnesium from turnings to powder the reaction between the magnesium and the sulphuric acid was going at the correct speed as before and the reaction happening seemed to look correct.

The results tables for the three tests are below:

Results 1:

Results 2:

Results 3:

Above are all the results that we obtained from the three experiments that we conducted. What I am going to do now is collect the mean results and to this what I have to do is add up the cm of hydrogen produced for the concentration of 100% and for 30seconds and divide it by 3 and so on:

What I can see from this table is that the most amount of hydrogen is produced when the concentration of the sulphuric acid is at its most powerfullest so when the concentration is pure acid. I can tell this because the most amount of hydrogen was produced at the end of the 100% reaction at an average of 73.3cm. so these results back one part of my prediction and it proved to be correct, but what I can also tell from average results is that as time goes on the amount of hydrogen produced decreased, so this proved my theory of what I thought might happen to be wrong. What I thought would happen is that as time went on the reaction would increase which would mean that the volume of hydrogen produced would be increased, but this was proved wrong because from my average table I can see that at the beginning 90 seconds was when we saw a greater difference between the first volume of hydrogen produced to the next amount in the space of 30 seconds for example from 30 seconds to 60 seconds the volume of hydrogen produced increased from 24.3 to 41.3 this is an increase of 20cm of hydrogen and from that the volume goes up to 54cm this is an increase of 13.3cm,but from 90 seconds onwards up to 210 seconds the rate at which the volume increases at is not that sufficient, it increases by 6,4 then 3. this shows that as time is going on the energy with in the reaction is running out which means that less heat is available for the particles to collide harder and faster to produce the reaction that we are able to see, what is happening as time goes on is that the reaction is loosing he heat energy which is causing the particles to move at a slower speed which means that they are now weaker and that they will not collide more often to produce the hydrogen which in over all basically means that less hydrogen will be produced.

After I have produced this table what I have done is that I have plotted these results onto a graph, this graph has all the average results on there so that I am able to compare the results and discus any anomalous results.

From the average results graph what I am able to see is that as the levels of sulphuric acid in the solution decreases the amount of hydrogen produced decreases as well. I am distinctively able to see the decrease as the concentration decreases and this is because the lines on the graph decrease at each stage. The average results graph also shows me that during the first 30 – 60 seconds as the magnesium ribbon comes in contact with the sulphuric acid the levels of hydrogen produced are low, but the thing is that they are low in volume but during the first minute or so is the period of time where I am able to see the greater range between the volumes. So when time does increase the volumes are higher in rate, but not higher between the ranges of each 30seconds. There seems to be more variation during the first minute and a half rather than afterwards. This is visible on the graphs by the steepness of the gradients in the first 30 – 60 seconds after 90 seconds the gradient starts to curve this is applied to all of the four concentrations.

Other general trends that I am able to se by looking at the graph is that as the time approaches to 210 seconds the lines seem to start to curve, this means that if we were to keep recording for a longer period of time the rate at which the hydrogen was being produced would of decreased and the reason to this is that once the energy in the reaction is lost it takes a longer period of time for the particles to come in contact with each other and collide to produce a reaction. I can also see that all four lines end at different volumes of hydrogen. I think that they all end correctly as they do not over take on and other, the reason why I say that they all end correctly is because as the concentration decreases the amount of hydrogen produced should decrease therefore the 100% concentration line should be the line which goes up the highest and the 7:3 concentration line should be the line where the line should end at the lowest amount of hydrogen produced in the whole experiment and this is what has happened therefore the lines are correct in that sense.

Evaluation:

I think that after we dealt with all the mishaps that we had during the course of the experiments the results obtained were of a good standard and they were reliable results which enabled me to analyse and evaluate them, therefore letting me produce line graphs for the results.

I think that the results that I obtained from my experiment are clear and accurate enough, I can say this because when we conducted the experiment for the last three tests we made sure that we followed the safety measurements to ensure that results will be accurate, we did not make any mistakes and remembered to change the water in the measuring cylinder and we also remembered to wash out the conical flask each time we finished with a particular concentration unlike in the preliminary testing .We also made sure that we kept an eye on the time so that we did not exceed the time limit of each experiment and we also made sure that we recorded the results of how much hydrogen was produced as accurately as we could trying to get it to the nearest cm., because we did all of the above that’s why I can say that the results obtained and accurate enough to be used to draw good conclusions and graphs for this investigation.

I have found some anomalous results and patterns in the individual experiments not the overall average. If you look at Test 1 graph, then you would see that the lines on the graph seem to over lap each other which is not meant to happen, because in theory what is meant to happen is as the concentration decreases so is the volume of hydrogen produced there for the lines should be in order with the 100% in coming up top followed by the 9:1, 8:2 and the 7:3 results line. But in test 1 results what has happened is that the results for the 9:1 concentration has overlapped with the 100% results. The reason for this is that the results of how much volume of hydrogen was produced for the 9:1 results was higher than the 100% results by 5cm. From the very beginning the 9:1 concentration produced higher results than the 100% concentration at 30 seconds 26cm of hydrogen was produced for the 9:1 testing whilst only 22cm of hydrogen was produced for the 100% concentration, at 150 seconds both sets concentrations had produced the same amount of hydrogen at 60cm, but then the 9:1 concentration over took the 100% and increased in the volume produced. The only surprising thing that I can see on the results of the 8:2 and the 7:3 lines is that the 7:3 concentration produced the same ending volume as the 8:2 concentration did at 40cm. I thought that this was unusual as I expected that the amount of hydrogen produced by the 7:3 would be less than the 8:2 but there does not really seem to be that much difference in the two sets of results. if I compare both sets of results ,by looking at the time and then across to what the results are for both sets at that time there only seems to be a difference of a maximum of 4 cm between the two which is not a lot compared to what I thought it should have been.

If you look at test 2 results then you would see that for the concentration of 9:1 and 8:2 the volume of hydrogen produced is very close, I can tell this because both lines only have a small distance between them, I think that this is an anomalous trend because if I look at experiment 3 results then I see that all the lines have a great distance apart from each other as the volume of hydrogen produced has decreased as the concentrations did. I referred to experiment 3 because this is the only experiment that has given an almost perfect line graph, as the concentration decreases so does the amount of hydrogen produced in this test which has given very defined results to analyse. The only hitch was that there is one point in the 7:3 concentration that does not fit in but apart from this all of the other concentrations produced a perfect line of best fit. The second experiments 7:3 results also seem to look very out of place, but I think this is due to the 8:2 results line as the 8:2 results line is very close to the 9:1 line therefore there is a huge amount space between the lines and also on the tables where the results are written down, the volume of hydrogen produced in the 7:3 concentrations is very low to the 8:2 concentration at times with a difference of 20cm.

I have some reasons to why my experiments have produced some anomalous results, although the experiment was carried out to the best of my ability and I tried to be as accurate as possible there are some factors that could have led to the anomalous results which will question the quality of the results. Factors such as:

A factor that might have affected the results is that even though I tried to measure the amounts of sulphuric acid out properly maybe at times the measurement were not correct; this will have an affect on the final results too. The measuring cylinder used could have been different at both times, the numbers used could have been wrong too.
As we split our group into pairs so that we are able to do two experiments at the same time, we may have done the experiment slightly different and even the slightest bit of difference is either measuring or calculating can lead to the overall outcomes being completely wrong/different.
We were using stop watches and as we were not allowed to stop the time when 30 seconds were up we would have to quickly record the results down, as it is not possible to record the results down exactly on time the measurements are always a couple of cm here and there and so this would also affect the overall results.
Some water from the measuring cylinder which had to be turned upside down in the water bath usually came out in this process and this would of also affected the results of the volume of hydrogen produced this is because it we started off with the whole thing not full then it would alter the measurements as you would be loosing a couple of cm each time off the actual volume this would mess up the hole of the results structure as they would not be even close to the actual volume.
As we split into pairs from our group of four we had to use two different sets of equipments and this would also alter the results because, in one group the conical flask and the delivery tube may not be working as good as the other group because maybe there was a breakage in the tube, so this would have affected the reaction from traveling up the tube in to the measuring cylinder which would mean that less hydrogen would have been produced or less would be visibly produced.
Another factor that would have affected the results is the timing of which the magnesium ribbon and the sulphuric acid was put at. This is because if the magnesium ribbon was added with the acid and then the rubber bung not shut immediately the reaction that is taking place would not be able to travel to the delivery tube and into the measuring cylinder this is because instead of the reaction being kept inside as the top is open the reaction would go outside and also oxygen would also have an input in the process which we do not want.

These are the main reasons to why the anomalous results may have been caused, there would be plenty of other little elements that would of contributed to the variation in results received but they are too small to be visible to the eye things like little breakages in the delivery tube or space around the rim of the conical flask and the rubber bung so that air was able to get in would have affected the results so that I was not able to get 100% accurate results, but I don’t think that it is possible to have an experiment where not a single element would affect the results of the outcome.

If I was to do this experiment all over again the things that I would change to make it a better experiment to give me better results would be to have more of a variation on the concentrations. I say this because I really thought that I would be able to see drastic changes in the structure of the results when the concentrations decrease acid and increase in volume of water, but this was not the case as I was not able to see that much drastic change and the reason to this was that we did not have that much variation between our concentrations we decrease by 10% each time which did not really enable us to see varied differences between the concentrations. So the next time that I do this experiment I would make sure that I have more range between the concentrations that I choose which will in return enable to give me a wider range of results to work with.

Another factor that I would change is the ‘Time Span’. I would record the results for longer this is because in this experiment I was not able to see if after a certain amount of seconds whether the volume of hydrogen decreases rapidly or gradually. Or even whether it decreases at all or does it stay stationary. This time around we stopped at 210 seconds right on the verge of the curve, so I am not able to tell what the reaction would have done but I can only predict that the volume of hydrogen would have decreased. This is because as the energy input dies out so does the energy released the output depends on the input.

Factors that I would keep the same is the mass of magnesium ribbon used this is because I think that 0.1g was the right amount and the type of magnesium which was ribbon, this is because when we used turnings and 0.2g of it the reaction happened too quickly so we found the perfect balance and I do not want to experiment with that unless I have to as we have fund the perfect balance and combination. I would also keep the equipment used the same this is because I think that the equipment that we used was perfect for the experiment and each piece of equipment did the job that we wanted it to do, and all the equipment was needed so I would not be able to take anything off the apparatus list. An addition that I would make is a clamp and a grasp this would be to hold the measuring cylinder, I would add the clamp and the grasp to hold the measuring cylinder so that one person does not have to sit there all the time holding the cylinder through the whole experiment. The clamp and the grasp would make the experiment so much simpler and then one person would be free to do another task. Another thing that I would change is the stopwatch, I would change this so that we are able to set the intervals and then we are able to leave the watch and after these intervals the watch would bleep or make a noise. The reason to why I would do this is so that we do not have to keep concentrating on the time also so that it would help decrease the levels of inaccuracies this is because when we are timing the process we often go over the time limit as we are doing the process manually but if it is done computerised then these inaccuracies would sure to decrease.

The new experiment:

The new experiment would consist of the same method as I am not changing the whole method totally I am only changing little elements in the experiment such as the equipment. I have produced a new diagram for the experiment below:

Diagram: