water bath - consists of beaker and water - the test tubes will be placed in here
heat proof mat - for saftey, where the bunsen is placed
goggles - for saftey, incase chemicals splash
pippet - to transport small amount of chemicals
test tubes - for carrying and heating chemicals
thermometer - for testing temprature
cross on cardbord - to see wheather the mixture has gone cloudy or not
I am going to use a concentration of i parts water this will increase the expirement time as so when we get to 60° their is still a resonable wait. this is so inaccuracy in starting and stopping the clock is hardly noticable.
keep the same
test tubes
flask
bunsen burner
tripod
water bath
heat proof mat
clock
person who starts and stops clock
thermometer
cross on cardbooard
concentration
The values i am using are (temprature):
25°
30°
35°
40°
45°
50°
55°
60°
Preliminary Expiement
When we mixed together the hydrochloric acid with the sodium thiosulphate the water turned cloudy. The black cross was no longer visiable. The higher the concentration of thiosulplate, the quicker the reaction.
Presice Results
We measured the temprature to the nearest 0.5°
We measured the time to 1 d.p.
We did the expeiment 8 times with differnet tempratures for reliable and accurate results.
Preliminary results
Results
I have found out that the higher the temprate of the thiosulthate and hydrocloric acid, the faster the reaction takes place.
SEE GRAPH 1
The graph has strong negative correlation, the grapth comes from the top left to bottom right, top left being low temp, long time, bottom left being high temp, low time.
Conclusion
From these results we can conclude that by increasing the temprature of the chemicals, the reaction rate is increased. This can be seen as the highest temprature had the highest reaction rate and only took seconds , where as the lowest temprature took seconds. The increase does seem to be proportional, as the gradient of the line seems to decrease by roughly the same amount each time. At this point we are able to answer our main hypothesis, with a yes. We can see that the collision theory is very important in this experiment. The collision theory states that if a solution is made hotter it means that the particles will move faster causing them to collide more. I did some further research and in the book Chemistry by J A Hunt and A Sykes it says that for every chemical reaction, there is a certain minimum energy needed in the collisions before a reaction can occur. This minimum energy is called the activation energy of the reaction.
Improvements
Possible problems with my coursework could have been the caused by human error. Firstly, there could have been error in stopping the stopwatch, although this would have been minimal. The chemicals could of also been measured incorrectly.
Overall, however, I think that this experiment has been successful because my prediction has been accurate which shows that the results are accurate. I have also made sure that the test was done fairly.