1) Wear safety goggles. 2) Hold bung from the end and not from the delivery tube to avoid injury. 3) If there is hot water in a beaker, hold the beaker from the rim. 4) Also place apparatus on the middle of the bench to avoid spillages and to avoid injury. How I kept it a Fair Test: > I kept the mass of the calcium carbonate chip at 0. 48g. > I kept the amount of nitric acid at 20cm3. > I equilibrated the equipment to the reacting temperature. > I took the same amount of time placing the marble chip in the boiling tube each time. Results Volume of CO2 lost Temperature (i?? C) 4i?? C Time (min) Run 1 Run 2 Average.
Time (min) Run 1 Run 2 Average This shows that at low temperatures, there will be a slower rate of reaction. Graph B shows that1:30 min and 4:00 min there was a significant increase in the loss of CO2. The rate of the reaction was 9. 66 cm3/min. Graph C is similar to Graph B as the reaction starts of slowly but increases as time passes. The rate of the reaction at 27? C was 12. 33 cm3/min. Graph D is also very similar to the two previous graphs as it starts slowly but gains speed towards the end. The rate of the reaction was 14 cm3/min. Graph E starts off very quickly but starts to taper off towards the end. The rate of the reaction was 35.
5 cm3/min. The final results show that my prediction was correct. I predicted that as the temperature is increased the faster the reaction would take place. Cool acid particles have little energy, therefore do not collide with the marble chips very often, and for a chemical reaction to occur you need many successful collisions between the acid particles and the marble chip. The hotter the acid, the faster the collisions and the reaction speeds up. The rate of a chemical reaction is increased by increasing the temperature and alternatively decreased by decreasing the temperature.
The increase in the rate of reaction with temperature can be explained by the collision theory. An increase in temperature increases the energy of the reacting particles. This makes more energy available for the breaking of bonds, which must take place in order for a chemical reaction to occur. Bond breaking is more frequent at higher temperatures. Increase in temperature Of reactants Evaluation The procedure we used was not as accurate as others that could have been used instead. Possible reasons for errors in this experiment were: > Top Pan Balance > Timer > Measuring Cylinder > Thermometer.
Another possible error in this experiment was that some of the Carbon Dioxide dissolved into the water in the measuring cylinder. The solubility depends on the temperature at which the water was. Also the size of the bubbles and the rate of production of the bubbles both contributed to the experimental error. Experimental Error 1. Top Pan Balance: This was only accurate to three decimal places, as the mass of the marble chip had to be 0. 48g the experimental error would be: 0 The experimental error for the top pan balance is relatively low.
2. Thermometer: This was only accurate tFor the thermometer as the temperature increased the experimental error decreased therefore I was more likely to find an error in my results at the lower temperatures.
For the measuring cylinder when the volume is small the error is large. The total experimental error for each temperature is: C- 4. 3003% error 37? C- 3. 9003% error As you can see, the lower the temperature the higher the experimental error. Improvements Marble chips- I could not ensure the size and mass of each marble chip, therefore could employ a sieve type mechanism. Range- I would spread the temperatures out more even; however have less error owing to lower temperatures.
Water- I would have water, which was saturated with sodium hydrogen carbonate (NaHCO3). As this allows little CO2 to dissolve in it. Bibliography: GCSE Chemistry Revision Guide: Co-ordination Group Chemistry: Hunt and Sykes Understanding Chemistry (A-level):Ted Lister and Janet Renshaw Appendix Includes Graphs A-E Sheryar Majid Chemistry Coursework 2000/2001 Dr Wright 1 Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section. o