Carrying out the Test: The things that I will be changing to help me discover the answer to this investigation are the:
-
Concentration of the acid because then I would know at the end of the experiment that if either the more amount of acid or the less amount of acid makes the reaction faster
-
The amount of water so then I would know what the water does to the reaction, make it go faster or slower.
Designing a fair test: All the things that I’m going to keep the same so that my experiment is fair are:
-
The sodium Thiosulphate solution because if we used some other solution like Copper Sulphate it would not be fair. This is because Copper Sulphate is less reactive and therefore would change the time of reaction with the acid.
-
The same acid because if used some different acid it would have a different effect on the Sodium Thiosulphate and therefore would not be a fair test.
-
The same room because if we did half the experiment in one room and the other half in another room if would not be a fair test because the rooms can have different temperatures.
Number of Measurements: I expect to try five different values for the acid and the water. So then I can assure myself that this experiment was no coincidence but a fact.
Plan:
- First I will gather all the equipment that I need and set them out on the working bench. Then I will get the acid, water and the Sodium Thiosulphate.
- After that I’ll have to wear the big bulgy safety goggles and get the stopwatch ready.
- As soon as I’ve done this I’ll pour out the amount required of acid in the beaker, followed by the correct amount of water and the Sodium Thiosulphate which will stay the same. After I’ve done this I’ve got to put the beaker on the ink cross which will help me with the experiment.
- Then I’ve got to stop the stopwatch as the precipitate gets thicker and the ink cross on the laminated card disappears.
- After recording the time taken I‘ll clear out the product produced which is Sulphur by the way, and repeat steps 2-5 for the other four measurements left.
- After the experiment is completely finished wash out all the equipment except the stopwatch. Take of the goggles and rewash your hands for safety reasons. Wash your workbench as well and your seat.
- Record your results in a table.
- EQUIPTMENTS NEEDED :
- Beaker
- 2 Measuring Cylinder
- Ink cross on Laminated card
- Goggles
- stopwatch
- Acid
- Dilute water
- Sodium Thiosulphate
Acid, Water and
Sodium Thiosulphate Ink Cross on Laminated Card
Working Safely: To make sure that nobody gets hurt or injured, we all will wear goggles for eye protection and at the end of the experiment, we all will wash our hands thoroughly. Plus any long hair should be tied back and there should be no running in the lab. The workbench should be cleared and shouldn’t have any thing on it. All bags and coats will be put to a corner in the room and shouldn’t be found under the workbenches because students may trip over the bags and coats and could have some serious accident.
Working Accurately: To ensure that all my measurements are accurate I will measure all liquids from eye level. I will also start the stopwatch as soon as all the reactants have gone into the beaker and not when some of the reactants have gone in.
The Measurements;
Graph or Calculations:
Conclusion: What I found out was that the more concentration of acid there is, the less time it took to react and vice Versa. Now looking back at my prediction, what I predicted was right and all thanks to all my science teachers since year seven, along with Mr. Ogunsola of course. The plots on the graph look pretty straight except (20, 16.66) which is a bit out of line.
Review: The conclusion above that I’ve just written does go along with the prediction that I wrote earlier on. The more concentrated the acid the faster it will react.
Accuracy: My Measurements were as accurate as I could make it. Because I measured all the substances from the eye level and was really sharp with the stopwatch.
Pattern Breakers: Only on of my points on the graph was out of line probably because I was a bit terrible on the stopwatch on this particular test.
Improvements: If I were given another chance to improve on this experiment I would have more tries with higher concentration of acid and with different amount of water.
