The purpose of this experiment is to look into whether altering the concentration of a solution will hold any consequence on the rate of the reaction. We are seeking to turn out that increasing the concentration will rush up the rate of the reaction.
The rate of a chemical reaction is the rate at which reactants are used up or merchandises are produced. In order to mensurate the rate of reaction we measure the sum of reactants used or merchandises produced over a certain period of clip. In our experiment we have chosen to utilize sodium thiosulphate and hydrochloric acid. This is because this reaction would be the easiest for us to observe the rate of the reaction.
Harmonizing to Le Chatelier ‘s Principle ; “if a system that is in equilibrium is disturbed, the equilibrium place will alter in order to oppose the distressing influence and re-establish equilibrium” ( 1 ) . Therefore if the concentration of a substance is increased so the reaction that removes that substance will be favoured in order to re-establish equilibrium in the system. So if we are increasing the concentration of the reactants so the forward reaction will rush up. Based on this information we can foretell that the rate of the reaction of Na thiosulphate and hydrochloric acid will rush up with increased concentration.
Since increasing the concentration will increase the sum of molecules we can foretell that there will be more effectual hits taking topographic point. The more effectual hits taking topographic point, the quicker the rate of the reaction will be.
Increasing the concentration of a substance will increase the rate of the reaction.
- 5 Equal Volume conelike flasks
- One 500cm? measurement cylinder
- Two 100cm? measurement cylinder
- One 10cm? measurement cylinder
- 8g of Na thiosulphate
- 35cm? dressed ore hydrochloric acid
- 1 electronic graduated table
- 1 filter paper
- 1 stop watch
- 1 piece of white paper with black cross
- First we had to utilize the electronic graduated table to mensurate out 8g of Na thiosulphate and so fade out the 8g of thiosulphate in 200cm? of H2O. This was done in the 500cm? measurement cylinder.
- The following measure was to utilize the 100cm? mensurating cylinder to step and pour 50cm? , 40cm? , 30cm? , 20cm? and 10cm? severally into the five indistinguishable conical flasks.
- In order to do certain that each conelike flask had a entire volume of 50cm? of solution we added 10cm? , 20cm? , 30cm? and 40cm? of H2O into the last four flasks.
- The following measure in the procedure was to utilize the other 100cm? mensurating cylinder to fix a dilute solution of hydrochloric acid. This was done by adding 35cm? of hydrochloric acid to 65cm? of H2O.
- Once all the solutions were prepared it was clip to carry on the experiment. We placed the conelike flask on the piece of paper over the black cross. We used the 10cm? mensurating cylinder to mensurate 5cm? of hydrochloric acerb solution and added this to the conelike flask. Equally shortly as it was added we started the stop watch. We observed the solution and every bit shortly as it turned a creamy-yellow and the cross could non be seen the stop watch was stopped and the clip was written down.
- This was so repeated on the other four conelike flasks.
- Once we had completed all the trials we cleaned out all the setup and repeated the whole experiment once more with the staying hydrochloric acerb solution so that we could compare the consequences.
|
Flask |
Sodium Thiosulphate concentration ( cm? ) |
Time ( s ) ( experiment 1 ) |
Time ( s ) ( experiment 2 ) |
|
1 |
50 |
32.72 |
24.16 |
|
2 |
40 |
33.80 |
27.90 |
|
3 |
30 |
54.60 |
43.01 |
|
4 |
20 |
84.92 |
71.01 |
|
5 |
10 |
197.40 |
158.19 |
From the above tabular arraies and graphs we can see that our hypothesis is right. Increasing the concentration of a solution will increase the rate of the reaction. We can besides see from the tabular array and the graphs that the rate of the reaction differed in experiment 2. The ground for this could be that when we prepared the dilute solution of hydrochloric acid we did non blend it decently with the H2O. This lead to there being a stronger dilute in the underside of the mensurating cylinder compared to that at the top of the measurement cylinder. This would hold affected the consequences as it means that in experiment 1 there was a weaker solution of hydrochloric acid used, when it came to experiment 2 we were utilizing the solution at the underside of the cylinder and that portion of the solution is stronger and more concentrated.
This really helped turn out our hypothesis as we can see that in experiment 2 the rate of the reaction was shorter. This is because there was a higher concentration of hydrochloric acid being added to the solution.
In the graph concentration vs. 1/time we can see that a consecutive line is formed. This means that there is an reverse relationship between concentration and the rate of a reaction. As the concentration of a substance is increased so the clip for the reaction to take topographic point is decreased.
From all of the above consequences from the experiment conducted we can reason that the rate of a reaction is affected by the concentration of a substance. As there is a higher concentration of molecules in the substance so there will be more effectual hits taking topographic point which means that the reaction will take topographic point much faster.
Chemistry Practical Investigation Preparation
In this practical probe we are traveling to look into the consequence that concentration has on the rate of a reaction. In order to make this we are traveling to carry on an experiment which involves adding different concentrations of a substance to another substance and so take note of the different rates of reaction, if any difference is to be seen. If a difference is seen so we can come to the decision that concentration does hold an consequence on the rate of a reaction.
Harmonizing to Le Chatelier ‘s Principle ; “if a system that is in equilibrium is disturbed, the equilibrium place will alter in order to oppose the distressing influence and re-establish equilibrium” ( 1 ) . Therefore if the concentration of a substance is increased so the reaction that removes that substance will be favoured in order to re-establish equilibrium in the system. So if we are increasing the concentration of the reactants so the forward reaction will rush up. Based on this information we can foretell that the rate of the reaction of Na thiosulphate and hydrochloric acid will rush up with increased concentration.
Since increasing the concentration will increase the sum of molecules we can foretell that there will be more effectual hits taking topographic point. The more effectual hits taking topographic point, the quicker the rate of the reaction will be. Thus we can reason in our hypothesis that increasing the concentration of a substance will increase the rate of the reaction.
The rate of a chemical reaction is the rate at which reactants are used up or merchandises are produced. In order to mensurate the rate of reaction we measure the sum of reactants used or merchandises produced over a certain period of clip. In our experiment we have chosen to utilize sodium thiosulphate and hydrochloric acid. This is because this reaction would be the easiest for us to observe the rate of the reaction. Other reactions that we could ‘ve used include the reaction that is represented in the undermentioned equation ; 2 NO + O2 = 2 NO2. The ground that we did non take this reaction is because it would be to complicated for us to supervise the rate of the reaction. It is for this ground that we chose to utilize the reaction between hydrochloric acid and Na thiosulphate.
In this experiment we are traveling to fix five mensurating cylinders each with different concentrations of Na thiosulphate in. This is to prove what consequence the different concentrations have on the rate of the reaction. In order to do certain that each flask has an equal sum volume we will add H2O to the each mensurating cylinder. The following measure of the procedure is to pull a cross on a piece of paper and topographic point it under the measurement cylinder. Once that has been done we will add a dilute solution of hydrochloric acid to each of the measurement cylinders. Since we know that this reaction produces a creamy yellow precipitate it will non be hard to mensurate the rate of the reaction. Once the hydrochloric acid has been added we will clip how long it takes until we can non see the cross on the paper, this means until the creamy xanthous precipitate is formed and the solution becomes turbid.
If our hypothesis is right so we will happen that the mensurating cylinders with a higher concentration of Na thiosulphate will take quicker to organize a creamy-yellow precipitate, therefore turn outing that increasing concentration increases the rate of the reaction.
Bibliography:
- M. Mann: Physical Science 12 text edition and workbook October 2007: page 16-1
- hypertext transfer protocol: //www.azete.com/view/48253
- hypertext transfer protocol: //www.science.uwaterloo.ca/~cchieh/cact/c123/coneffec.html
