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Introduction

Rate of reaction investigation Introduction In reactions involving only gases, an increase in the overall pressure at which the reaction is carried out increases the rate of reaction. The increase in pressure resulted in the gas particles being pushed closer together. This meant that they collided more often and so they reacted faster. A chemical reaction is a process by which one or more substances called reactants changes into one or more other substances, called products. A reaction is when two particles (reactants) join to form a new product or products. Rate is a measurement of the change that happens in a single unit of time, any suitable measurement can be used such as seconds, minutes, hours or even days. A rate of a chemical reaction is how fast the reactants react. In general, to find the rate of reaction, you should measure either the amount of reactant used up per unit of time. This investigation is about the effect of temperature on the rate of reaction. The equations of this investigation: Calcium Carbonate (Marble) + Hydrochloric Acid--> Calcium Chloride + Water + Carbon Dioxide Here are the four methods that can use to measure the rate. Method 1 Method 2 Method 3 In method 1 is a water displacement method; the rate of the reaction can be measured by using the measuring cylinder. As the water go down, this mean the carbon dioxide is displacing the water. There are another way of measure is that we can court the number of CO2 bubbles but this is hard to measure because the bubbles could be large or small. In method 2 is a gas syringe method, the rate of reaction can be measure by the gas syringe. The carbon dioxide can be collect by gas syringe. In method 3is mass loss method, as the carbon dioxide is given out, the mass of it will reduce. ...read more.

Middle

Although these factors will affect the end result so long as they are kept constant throughout then it should not matter too much. To get the best possible results I need to use the equipment in the best possible way, I could twist the gas syringe back and forth so as not to get the syringe stuck, which would affect my results. I will need three readings for each concentration and later if I need to repeat any experiments I can. An important point is that I must use the right amount of acid and the best sized amount of marbles. I did an experiment beforehand to give an idea as to what to do in our investigation. It was the reaction between marble chips and hydrochloric acid. This was a very good thing to do because it showed me how to use the equipment properly and safely and gave an idea as to what was to come. Fair Test To ensure that our results were accurate and reliable my group and I had to take into consideration the following points. 1. The fact that each marble chip had its own surface area, which could have affected our results. To try and over come this problem we used chips that weren't too big, yet weren't too small so that the surface area only differed a little. 2. The hydrochloric acid used was of the same molar solution for all experiments. 3. We repeated the experiments three times and then found the average of our results. 4. The apparatus used was the same for all experiments to ensure that the experiments were fair. 5. The temperature was kept changing within each experiment. 6. And lastly we used a more accurate measuring cylinder, so our results would be reliable. Each time I repeat the experiment I will keep the surface area of the marble chips, amount of acid used and the amount of carbon dioxide to be collected the same. ...read more.

Conclusion

Reading Error: The error due to the guesswork involved in taking a reading from a scale when the reading lies between the scale divisions. The amount of marble chip I put in each experiment are not the same. Although I am using the medium size of marble chip but there are also some powdered chip on it, so it makes the experiment unfair which affect the accuracy of the results I get from the experiment. Therefore, to ensure the result is accurate, I will weight the marble chip every time I do the experiment. Also to make my result more accurate, I compared my readings to someone else reading from the class. I also made an average from my 3 result which will make my result more reliable. The experiments were fair tests to a certain extent but there was a certain margin of error because the results recorded were only to the nearest cm� and the values of the controlled variables were not exact amounts so the may have been slightly differently each time which would have affected slightly the reliability of the results. This would have made little difference to the results though as the volume of gas was only measured to the nearest cm. I think that there were enough evidence for me to drawup the conclusion. To improved my experiment and make my result more accurate, I will increase every 5 degree to do the experiment and also I will extend experiment by changing the surface area and keeping the temperatures the same to investigate the effect of surface area on the rate of reaction because if I do that, I can have a strong evidence to support my prediction. Furthermore, I will change the concentration used so that I can see the effect of the concentration on rate of reaction which can help me to support my prediction. Moreover, I will use different catalyst because different catalyst has different effect on the rate of reaction. Martin Man 11O ...read more.

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