Thursday, January 30, 2020
Combustion of a series of Alcohols Essay Example for Free
Combustion of a series of Alcohols Essay The larger the surface area over which the reaction can occur, and the faster the reaction rate. This is because small particles have a large surface area in relation to their volume more particles are exposed and available for collision this means more collisions take place so the reaction is faster. Oppositely large particles have small surface area in relation to their volume fewer particles are exposed and available for collisions. This means less collisions and a slower reaction. To ensure that my test will be fair I have to keep all these factors the same except for one, the concentration. I will have to control the temperature of the room; the particle size will be same as I will shake the substance so it will be equally diffused. Hypothesis I predict that the higher the concentration of hydrochloric acid the faster the reaction occurs. The lower the concentration the slower the reaction is. Supporting information I base this hypothesis on the collision theory as I know that concentration affects the reaction greatly. This is because when there is a higher concentration the particles are closely packed together and there are more successful collisions occurring, thus making the reaction happen quicker. Preliminary For my preliminary I have used various concentrations of hydrochloric acid and 4cm of magnesium ribbon. The concentrations that I decided to experiment was he reason why I am doing a preliminary experiment is so that I know which concentrations of hydrochloric acid to use that would make my experiment more convenient. For the actual preliminary experiment I reacted hydrochloric acid with magnesium ribbon to see how long it took. I did this by watching when the magnesium ribbon had stopped reacting and disappeared. Although I was just using this method to find out how long a particular concentration took to finish reacting I attached a glass syringe to my conical flask to observe how much hydrogen was being produced, so that I could be prepared when it came to doing my actual experiment. The table below shows the amount of hydrochloric acid and water I used for a certain percent and the time taken for the magnesium ribbon to fully stop reacting. Volume of HCL (ml) Volume of H2O % of concentration Time taken for the mg ribbon to disappear (in seconds). From looking at the information from my preliminary I have decided to use the following concentrations for my actual experiment: 20%, 40%, 60%, 80%, 100%. The reason why I have decided to use these percentages of concentrations is because even though it shows a variety it will not be as time consuming as 10% concentration of hydrochloric acid took 1205 seconds which was approximately 20 minutes. 10% concentration took so long that I didnt have enough time, there for I left it anonymous. I also realised that even though I experiment 20% of hydrochloric acid it will still take long, there for I decided to lower the amount of magnesium ribbon so I decided to use 3. 5cm instead of 4cm. From doing my preliminary I have decided to repeat my experiment 3 times because this will give me a more reliable results to choose from and an average. This also will be less time consuming then repeating it 5 times. The preliminary experiment also helped my produce a better plan because I learnt that for 100% of concentration the reaction takes place quite quickly there for watching the stop watch had to be done very quickly but correctly. Plan: The apparatus that I will be needing for experiment and why: 3. 5cm of magnesium ribbons to react with HCL Stop watch to measure how long it took for the magnesium ribbon to stop reacting. Hydrochloric acid (1m) to react with the magnesium ribbon Measuring cylinder to measure the concentration of H20 and HCL Pipette to measure smaller concentrations of H20 and HCL Retort stand to hold the syringe Conical flast for the reaction Thermometer to measure room temperature Syringe to measure the volume of hydrogen produced Ruler to measure 3. 5cm of magnesium ribbon Scissors to cut the magnesium ribbon Distilled water to add with the concentrations of HCL Sand paper to sand the magnesium ribbon 1. I will firstly collect all the equipment needed for my experiment, then measure them to the exact measurement. I will start with 100% concentration of hydrochloric acid which will contain no distilled water and 10ml concentration. I will then measure my magnesium ribbon to 3. 5cm and sand it 8 times on each side making sure it is fair. Using the measuring cylinder and pipette I will put my hydrochloric acid into the conical flask. 2. To ensure that the magnesium ribbon doesnt get stuck I will coil the magnesium ribbon with a clean sterilised ruler. 3. I will then attach the syringe onto the retort stand. Then I will attach my conical flask with the syringe. 4. Because I want this test to be fair I cannot do it on my own so my partner will start the stopwatch as soon as I drop the magnesium ribbon into the hydrochloric acid. Then I will seal the conical flask with the cork. 5. Every 10 seconds my partner will tell my the time on the stop watch and then I will look at the syringe to see what the volume of gas produced is. I will note this down very quickly. 6. After the reaction has fully stopped. I will empty the conical flask, then start the same process again but for 80% concentration which is 8ml of hydrochloric acid and 2ml of distilled water. This process will happen for all 5 concentrations. 7. After experimenting all 5 concentrations I will repeat the same process 3 times to ensure my results are fair and reliable. Keeping my experiment fair: making sure all equipment is clean from unwanted substances. sanding the magnesium ribbon same times on each side. hile my partner starts stop watch, I quickly drop magnesium ribbon so it is done at the same time. Use the same length of magnesium ribbon, checking it is exactly 3. 5cm. Safety issues:aking sure I wear my goggles at all times. Tying hair up. Tuck in stalls, and stand up during experiment. Making sure I handle all the equipment correctly. If there is any spillage, quickly wiping it with paper towels. Obtaining evidence: 100% Time (sec) Volume 1 Volume 2 volume 3 Average 1.To find my average number of hydrogen produced I added the 3 volumes together then divided by 3. The answer most close I decided was my average. 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.