In this experiment, we shall be adding sodium thiosulphate to hydrochloric acid together and placing a drawn cross underneath and seeing how long the rate of reaction lasts until you cannot see this cross. Before the reaction starts, the liquids are both clear. When added they turn cloudy and milky with a yellow tinge to it, due to the sulphur released. Na2S203 (aq) + 2HCL –>2Nacl (aq) + H20 (l) + SO2 (g) + S(s) Sodium thiosulphate + hydrochloric acid –>salt chloride & water + sulphur dioxide + Sulphur The aim of this experiment should be to see how every single factor influences the rate of reaction.
The elements we are concentrating on are: Concentration� Surface area/Particle size� Temperature� Catalyst Accident Theory: To be able to understand prices of reactions, we employ this model 1) All chemicals are made from debris (atoms/Molecules) 2) The particles have energy and can maneuver 3) Reactions only happen when allergens collide 4) Some accidents are not successful. Thy must have enough energy to respond Particle size.
6 surfaces for that reason a slow reaction due to a smaller surface area Small poker chips therefore a faster effect because of a bigger surface area.
The collision theory model talks about why more compact particles possess a quicker reaction Temperatures Lower energy therefore allergens move gradually so a slow response More energy therefore allergens move faster so even more collisions, thus faster reaction The collision theory points out that raising temperature makes reactions more quickly. Concentration Attentiveness measures how many skin moles per 1000cm3 KEY 1mole=6 x 1023 particles one particular Litre= 1dm–>1000cm3 1dm x 1dm x 1dm= 1cm3 Diluted –>( 1 mole/litre) (1 mole/dm3) Even more concentrated therefore 2 moles/dm3–>.
So you will find two times as many particles in the same position, therefore even more collisions, therefore a more quickly reaction. If we double the concentration, there are twice as many particles inside the same space, so therefore twice as many crashes so faster reactions. Catalysts Catalysts offer an alternative way to reaction with lower service energy. Conjecture In this test my conjecture is that the cross will vanish faster because the temperature gets more comfortable. This is because since it gets warmer, the atoms vibrate more and move around more rapidly.
This means that when it mixed with the sodium atoms, they hit each other atoms faster and harder which result can be forcing the response to happen faster. When the heat is decreased the opposite happens because the atoms have less energy and would hit less solid so it will take a longer period of time to find the same consequence. My prediction of how the graph could look like are these claims: The chart begins to go down because for certain temps as the atoms drive more moreattract energy and hit more making the cross seem to disappear quicker.
A theory, which backlinks into this experiment, is definitely the collision theory. This is because the collision theory deals with atoms vibrating because they receive more energy and they then hit more often. Device o 1 thermometer to 1 beaker o 2 measuring cylinders o 1 conical flask o one particular tripod o 1 gauze o one particular heatproof mat o 1 stopwatch o 1 Bunsen burner o X panel o you pair of tongs o 1 pair of safety glasses Method u Measure 10ml of hydrochloric acid into conical flask o Warmth over Bunsen burner until desired high temperature o Take out immediately and place on top of hand-drawn flask.
um Add 25ml of Sodium thiosulphate um Time to see how long the cross takes to go away completely o Repeat three times o Repeat all over again to the high temperature 5 my spouse and i? over the last temperatures. Safety Some goggles will be worn through the heating part of the experiment to be able to protect the eyes. When handling popular beakers and measuring cylinders a pair of tongs will be used. A gauze and heatproof mat will be used while heating to avoid any harm to the equipment. Saving o 3 times o Within a table Reasonable Test For my results to be valid the research must be a reasonable one.
I will use the same judgement whenever for aiming to see when the X has disappeared. I will make sure that the measuring cylinders for the HCl and thiosulphate will not be mixed up. How much HCl will be the same whenever, and the volume of thiosulphate will be fixed at 12-15 cm3. Through the heating stage of the experiment, a green flame to be used throughout. Likewise the same Bunsen burner and gas faucet will be used to take care of continuity. Most of these precautions could make my outcomes more reliable and maintain anomalies at a minimum so hence make the complete investigation easier.
The only modify that will happen will be that the temperature of the Hydrochloric chemical p will go up 5 my spouse and i? every three times ANALYSIS Benefits Temp (i? c) Time (s) you 2(s) 3(s) Average(s) Coming from my results I can determine that as the temperature of the hydrochloric acid increases, the rate for reaction likewise gets higher. This really is in line with the collision theory, which describes that since the acid receive hotter, the atoms get more energy and vibrate more.
When the two liquids strike, the atoms are forced together also because they are moving more they will hit quicker and harder therefore triggering the reaction to speed up and the solution to change a yellowish colour faster so the cross seems to vanish quicker. The graph demonstrates that the theory works for this experiment, as it is a curved line. The sketch chart I received in my prediction matched the actual graph showing that the science I used to make clear my prediction was appropriate. Evaluation Taking a look at my effects I can declare they were quite reliable and accurate. I had developed one anomalous result even after a typical over three measurements.
This was at 30i? and I think could have been because the water we rinsed the beaker out in may well have remained in and caused the reaction to decelerate. I can admit looking at my personal results when I repeated benefits they were quite close together. I do believe that I would the test quite well though I found it hard to spot in which the exact second when the combination disappeared. That is why we do an average over 3 measurements. To improve the experiment We would need to have an extremely accurate stopwatch to period exactly how long the get across took to dissappear so I could be really correct in my outcomes.
Ways in which I could extend this experiment in order to use a several size of mix so that it will not disappear at such a minimal temperature by doing this I could go on to see if the collision theory is still right at higher conditions.???? Chemistry Sharna Sutherland Present preview only The above critique is unformatted text This student drafted piece of work is one of many obtainable in our GCSE Patterns of Behaviour section.
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