We began our 2nd trial run and we were more aware of what we were doing and that is when we spotted that we were not making sure that we were putting the same amount of Magnesium strips we realized this because we had some that were larger than other strips and others that were smaller, so what we done is we got a ruler and we measured and cut each Magnesium strip that was exactly 1cm long and this was our second mistake also not realizing that, we had not measured the temperature of the water this was informed by our teacher so we got a thermometer and measured a water and got our average temperature and we kept it constant through out the experiment.
Our 3rd trial run was the way the experiment was meant to be done we done it without any mistakes and we were ready for the real thing now. We had to do some more research into which metal we were going to used the only other metal we had in our laboratory was Calcium Carbonate and that was far to weak as they do not give off as much gas as Magnesium and they quickly react and they disappear a lot quicker than Magnesium so that is why we chose Magnesium as our metal and the most concentrated acid we have in our laboratory was Hydrochloric Acid and the most concentrated we could get was 2.5 and this was powerful enough to make magnesium react very fast indeed. We also made sure that diluted water was only used to vary the concentration of the Hydrochloric Acid because if it was distilled or any other type of water it would not have been a fair test. We used the different concentrations of Hydrochloric Acid and they are as followed: 0.5, 1.0, 1.5, 2.0, and 2.5 0.5 being the one that is least concentrated the school had already provided this for us we did not have to dilute the Hydrochloric Acid ourselves.
When we finished our trial run we looked at our results and we compared them to our hypothesis and my hypothesis turned out correct and I have written that in my write up.
Collision Theory:
In our preliminary work we researched on how the collision theory is involved with the experiment we are doing, the way in which it is involved is we are trying to find out if in concentrated Acid the rate of reaction is affected well if a concentrated Acid has more atoms then it is more likely for the atoms of the Magnesium strip to bump into the Acidic atoms unlike in a more weaker concentration of Hydrochloric Acid which has fewer atoms to bump in that means less heat is generated. The higher the temperature the faster moving they are. Particles have more kinetic energy, this means that they are moving faster and will collide more often. More concentrated solutions contain more partials in the same space making them more likely to collide the increase in the number of collision with sufficient energy increases the rate of reaction.
When you apply heat to a reaction the atoms will bump into each other quicker and more often. If it is concentrated the atoms are closer and the atoms bump into each other and react faster. The larger the surface area the less time it takes to react and this is because the atoms have a lot of area and might not bump into each other. If you add catalysts they will speed up the rate of reaction but not get involved with the reaction.
Diagram of The Collision Theory:
Variables:
Independent Variables:
- The Concentration Of The Acid
We will keep changing the concentration of acid to find out which is quicker and gives of more gas.
Dependant Variables:
- The amount of gas produced in 1 min
We are making the time limit 1 minute as we need to have a long time because of the weak concentrated acids.
Controlled Variables:
We have to keep the Magnesium strip the same as it might not be a fair test because we would be using more or less each time if we never measured it.
We have to keep the temperature constant as heating it might make the reaction faster or if it was colder it will slow the reaction time down.
We have to keep the volume of acid the same as it might not be a fair test and we are keeping a constant amount of 100ml.
Catalysts would not make it a fair test as it speeds up the rate of reaction although it does no get involved with the reaction but will speed up the reaction and give us a bad result.
We must not add any amount of pressure to the experiment and also we do not have any equipment to do such a thing.
We should not shake the conical flask as this might cause the atoms to bump into each other even more which is speeding up the rate of reaction and this would not make it a fair test.
We have to have a pipette for each Hydrochloric Acid concentration as if we get them mixed up they might not be a fair test.
We have to change the conical flasks with the Acidic Concentrations other wise it might not be a fair test.
Safety:
We have to have goggles on at all time to stop the Acid getting in our eyes and we also have to be very careful and aware of what is happing.
Diagram:
Method:
First we set up the apparatus and we put on our goggles for protection against Acid in our eyes we got five conical flasks and we poured into each one a different concentration of Hydrochloric Acid we got fifteen pieces of Magnesium each correctly measured and weighing the same and put the first 5 into the conical flasks and then put the syringe on top of the conical flasks we then started the timer for one minute and after one minute we measured the amount of gas took down the results for the first three tests and then we done the same process again two more times and then we done it again three more time and again three more times in total we done this nine times this was our trial run we then when we were confidant started to begin our real experiment.
When we began our real experiment we took caution in what we were doing and we took our time and did not rush anything.
We measured in a beaker 100ml of Hydrochloric Acid we used a pipette specially for this concentration of Hydrochloric Acid then we done this again four more times into four more beakers and poured all the five solutions into each one of the conical flasks then we measured 15 Magnesium Metal strips all measuring 2.5cm and we placed the first five into the five conical flasks one in each conical flask and then we put the syringes on top of the conical flasks and we measured the amount of gas that was given off, we wrote the results and done this again two more times until we were done with the experiment.
Conclusion:
I think that the stronger the concentration of the Acid the quicker the rate of reaction and the more amount of gas is given off we found out on average that the Hydrochloric Acid with the concentration of 2.5 is the one that gives off more gas and reacts the fastest. This concludes my hypothesis of the Acid which is most concentrated gives of more gas and reacts faster that the others.
I think I was right that the more concentrated the Hydrochloric Acid the more the rate of reaction will rise and rise this is because of the density of the atoms in a more concentrated Acid then a less concentrated one. So therefore I was correct in my hypothesis and I conclude that my prediction was correct.
Evaluation:
We had about five anomalies the first one was that we never used a pipette for each Hydrochloric Acid concentration this could have rewind our results because the weaker concentration could have mixed with the highly concentrated one and we could have had a really adequate mixture therefore ruining our experiment.
Our second anomaly was we got the number 23 as a result for a weak concentration and the rest did not make it to 21 so this must have been a mistake due to a mistake in our test probably we used the same pipette or we used more Magnesium than needed.
Our third anomaly was we never accurately measured the amount of Hydrochloric Acid in a conical flask we just poured it in we had to measure it with a beaker in order so it can be a fair test. We fixed this problem this is a classic mistake due to laziness.
Fourthly we never accurately measured the Magnesium this could have dramatically affected our results because if we added more it could have given off more gas or if we put less it would not have given off enough gas so we can measure it.
Our fifth and final anomaly was that we never measured the temperature of the Acid because we should have this is because if it is heated It could speed up the rate of reaction or if it was cold water it could decrease the rate of reaction and this would have had a dramatic affect on our results.
Our independent Variable was correctly done as they were each 0.5 from each other and we got the weakest and the strongest we could have in our laboratory and they were correctly used.
It was not easy doing a fair test as everything had to be perfect and right and nothing could go wrong and we had to keep the heat of the Acid constant and we had to measure accurately the Magnesium strips and the mount of Acid also we had to use the same timer make sure nobody made a mistake it was not easy to do a fair test it is very hard incredibly hard.
We had very accurate measuring and we measured anything that could be measured we measured the Acid and the Magnesium also the amount of gas was given off. It was very hard.
We could have improved our method of being aware of things such as stopping the timer when one minute is up and measuring accurately and we had more accurate instruments available but they were in use and we could not use them at the time. We could have used our data logging system if it wasn’t in use by another teacher.
I think we gathered all the possible information for this experiment we went and done some research on the internet and we looked in some textbooks for information and we put all our information together and we made a very accurate experiment and the experiment was successful in everyway.
One thing we could have improved on is the amount of Magnesium we used we should have been using more because we need more accurate results because with the amount we used it barley gave off any gas at all so that is the one thing we can improve on.
Another thing we could have improved is we could have also used a measuring cylinder and that would have mad our results more accurate and we needed a syringe with accurate measurements our measurements only went up in fives so we did not have any mm which means it had to be a whole number never to a decimal place that is another thing we could have improved.
Final Conclusion:
I think I done very good in this experiment and I worked with the right people and made a very fair experiment and it turned out to be great and I am sure I will enjoy doing another experiment like this
Safety:
We wore goggles at all times and were aware of what is going on also we were very careful with the very concentrated Acid as it was very dangerous and irritant.
