The Tension of a Gas is Square Rateable to Its Absolute Temperature - Research Paper Example

Name: Institution: Tutor: Date: Abstract This experimental work explores the behavior of gasses under varying conditions of temperature, pressure and volume. It explores Boyle’s law in the first section and constant volume law in the next part of the experiment Part 1 Introduction Over a long period of time, scientists have tried to review and analyze Robert Boyles work on the relationship between various properties of gases. This experiment delves into the same problem in order to provide a basis for better understanding of the basic laws of gasses. This experiment tries to find the relationship between the volume and pressure of a gas when the temperature is kept constant. Theory Boyle’s law states that at constant temperature, the volume of a given amount of gas varies inversely with pressure. This is to say that when at constant temperature, the product of pressure and volume for a certain amount of gas is constant. Matter consists of solids, liquids and gases. These three states are only set apart by the amount of intermolecular forces that hold their particles together. The rate of movement is therefore different in each of these states. Temperature is a gauge of the kinetic energy possessed by these particles. At a certain temperature, the molecular forces that bind the particles together have to be higher than the kinetic energy. But in cases of ‘ideal gasses’ it is assumed that the intermolecular forces are negligible. Therefore, the volume of a given amount of gas will vary inversely with the pressure at constant temperature for an ideal gas. P1VI=K or P1V1=P2V2 where: P=Pressure movable piton V=Volume thermometer K=Constant pressure gauge The above apparatus can be used to show this relationship with the piston used to vary the volume of the container. When the piston moves down, the volume decreases. This leads to an increase in the number of collisions per second per area. Methodology The equipment included a cylindrical tube within which the volume can be varied. The experimented was started by opening the release valve on the tube to set the pressure to atmospheric pressure,0 on the gauge that is 1 bar absolute and pulling the connecting rod out of the 50ml volume position .this could be observed by viewing the first calibration mark. The release valve was then closed and the connecting rod pulled out until the 100ml calibration mark. The value on the meter is recorded. The experiment was carried out very first due to leakage from the apparatus. This process was repeated until the 150ml, 200ml and 250ml had been reached while recording the temperature and pressure at each volume. The procedure was then repeated 5 times. Results The following results were obtained from the experiment Volume(ml) pressure Average(bar) 100 0.80 0.70 0.70 0.80 0.75 0.75 150 0.60 0.60 0.65 0.66 0.60 0.62 200 0.40 0.45 0.45 0.40 0.40 0.42 250 0.30 0.30 0.35 0.30 0.30 0.31 But the reading of 0 to 1 bar on the pressure gauge was a relative measurement. It was therefore imperative to convert it to an absolute value by adding 1 to each reading Volume(ml) Pressure(bar) Average(bar) in PSI 100 1.80 1.70 1.70 1.80 1.75 1.75 150 1.60 1.60 1.65 1.66 1.60 1.62 200 1.40 1.45 1.45 1.40 1.40 1.42 250 1.30 1.30 1.35 1.30 1.30 1.31 Given that 1 bar=101.3kpa and 1bar =14.5 PSI Volume(ml) Pressure in bar Pressure in PSI 100 1.75 25.38 150 1.62 23.49 200 1.42 20.59 250 1.31 19.00 PV=K 100ml *1.75bar=175 150ml*1.62bar=243 200ml*1.42bar=284 250ml*1.31bar=327.5 Pressure(ml) volume 1/v 1.75 100 0.01 1.62 150 0.0067 1.42 200 0.005 1.31 250 0.004 Error The results obtained for PV=K did not give consistent results. This may have been due to: 1. Leakage occurring during the experiment may have affected the volume and pressure readings 2. Human error in the calibration of the apparatus and the reading of the results might have affected the results 3. Slight change in temperature during the experiment might have affected the results The graph shows that as the pressure increases, the volume reduces thus proving Boyle’s law. Part II Introduction The aim of the experiment was to determine the relationship between pressure and temperature at constant volume. Theory The pressure of a gas is directly proportional to its absolute temperature. An increase in temperature results in a corresponding increase in pressure of the gas. This is at constant volume. The temperature is measured in Kelvin and when related mathematically it gives: pressure ∝ Temperature. As previously stated, temperature is the average measure of kinetic energy therefore particles tend to move faster when the temperature increases. These means the gas particles will hit the container walls harder and more often. This increase in strength and rate of gas hitting the wall causes a rise in force that’s exerted on the container wall hence increased pressure (Sang 97). Or Pressure/temperature =constant P/T=k P1T1=P2T2 Where P is pressure in atm/bar, T is temperature in Kelvin and k is a constant This is Gay-Lussac’s law or constant volume law (Srivastava and Jain 423). Methodology The apparatus for this experiment consisted of a sealed cylindrical tube within which the temperature could be varied. A water manometer was also provided with each millimeter difference between the levels of water being equal to 1/10000 bar. The experiment was started by disconnecting the silicon tube from the nozzle on the end of apparatus to reset the pressure in the apparatus to ambient. The silicon tube was then reconnected to its initial place on the end of the apparatus. The initial values of temperature and pressure were then recorded. The heating element was turned on and values of temperature and pressure were further recorded after every 10 seconds. Results and Analysis Pressure in bar Pressure in atm temperature 52.3 0 0 24 53 0.7/10,000 0.00007 24 53.5 1.2/10000 0.00012 24 54 1.7/10000 0.00017 24 54.8 2.5/10000 0.00025 26 55.5 3.2/10000 0.00032 26 56 3.7/10000 0.00037 27 57 4.7/10000 0.00046 28 57.7 5.4/10000 0.00053 29 58.5 6.2/10000 0.00061 29 60 7.7/10000 0.00076 30 63 10.7/10000 0.00106 31 64.5 12.2/10000 0.00120 32 65 12.7/10000 0.00125 35 65.7 13.4/10000 0.00132 37 66.1 13.8/10000 0.00136 37 67 14.7/10000 0.00145 37 A GRAPH OF PRESSURE vs. TEMPERATURE Gradient=change in y values/change in x values. Taking two points on the line (24, 00007) and (26, 0.00030) Change in y=0.00023 Change in x= 2 0.00023/2=0.000115 To find the absolute temperature by extrapolating the line of best gives a value of absolute zero as 24 degrees =297 Kelvin. The error in the experiment by calculation is given by: %error= (𝗅 observed 𝗅 –𝗅 true 𝗅)/𝗅 true 𝗅 × 100 (297-273)/273 ×100 =8.79% The value of absolute zero did not coincide with the expected value of -273.15 degrees Celsius or zero Kelvin. This error may have been caused by: 1. Incorrect reading of the water meniscus leading to incorrect reading of the pressure values 2. Leakage of gas from the cylindrical tube may have occurred leading to an error in the values of pressure obtained. 3. The line of best fit might have not been placed at the best point for optimal accuracy. This reasons combined with laboratory inexperience provided an inaccuracies that led to a significant error in the value of absolute zero. Conclusion The results prove, with a small percentage error, that Boyle’s law and constant volume law (Gay Lussacs) are both right in principle and under ideal conditions; the results would accurately depict these. Continued practice in these experiments would help avoid the aspect of human error in the results obtained. Work Cited Sang David. Cambridge IGSE physics course book. Cambridge: Cambridge university press.2010, print. Srivastava AK, and Jain PC. Chemistry Vol (1& 2). New-Delhi: FK publications.2008, print. Read More