Exploring the Behaviour of Gases

Exploring the behaviour of Gases Part I 1. By visiting the site link given in the lab guideline lead to the simulation page of virtual lab. 2. Going to intro and choosing only one type of particle (red particles) as shown in figure 1. 3. The pressure, temperature and volume are recorded in table 1. For volume it is assumed that container have height and depth of unity. Table 1: Pressure (atm) 5.8 Temperature (K) 300 Volume (nm3) 10 Figure 1. Parameters record for light particles for first pump 4. Give one pump of gas and observe the behavior. How would you describe this? Answer: Giving one pump to the gas make the pressure almost double while all other parameters remains same. Values of pressure, temperature and volume are calculated in the table 2 and also shown in figure 2. For volume it is assumed that container have height and depth of unity. Table 2: Pressure (atm) 11.7 Temperature (K) 300 Volume (nm3) 30.0 Figure 2. Parameters record for light particles after second pump 5. By holding volume and temperature constant and giving more pumps to particles values are recorded for different pumps in the data table below. Table 3: Number of particles 50 100 150 200 250 Pressure (atm) 5.80 11.7 17.5 23.4 29.2 6. Is there a relationship between the number of particles and the pressure? Briefly describe this. Answer: Yes, there is direct relation between number of particles and the pressure. From table 3 it can be seen increment in number of particles increase the pressure in the container and vice versa. 7. What is the pressure in the container due to? (what assumption are we making?) Answer: The pressure in the container is due to collision of particles with the wall of container. Main assumption we are making for the analysis purpose is temperature and volume remains constant as the number of particles is increased in the container. Part II: Experiment 1- Constant Volume 1. By giving one pump of light gas particles into the chamber and choosing to hold the volume constant by selecting option in the upper right-hand corner. 2. The initial temperature (in K) and pressure (in atm) in the chamber are recorded in table below. Table 4: Pressure (atm) 5.8 Temperature (K) 300 Volume (nm3) 10.0 Figure 3. Parameters recorded at constant volume for first pump 3. Using the slider at the bottom of the simulator for addition of heat until the temperature become double. The pressure goes up during heating and the new pressure in the chamber is shown in figure 4. Figure 4. Value of pressure at double temperature 4. By keeping the volume constant and the number of particles constant, pressure is recorded for change in the temperature in table 5. In the analysis following are the parameters Independent variable is: _____Temperature____________ Dependent Variable: ________Pressure____________ Constants: ______ Volume of container and the number of particles _______ Table 5: Temperature (K) Pressure (atm) 300 5.80 350 6.80 400 7.80 450 8.80 500 9.70 Figure 5. Relation between Pressure and Temperature at constant volume Describe the graph and relationship: The temperature and pressure have direct relation at constant number of particles and constant volume. From figure 5 it can be seen with increase in the temperature, pressure in the container is going to be increase and this increase is linear with direct relation. Experiment 2 – Temperature 1. By giving one pump of light gas particles into the chamber and choosing to hold the temperature constant by selecting option in the upper right-hand corner. 2. The initial pressure in the chamber after one pump comes out 5.8 atmospheric (atm). 3. By choosing the handle on the left of the chamber and sliding it to the right as far as it will go give information for answering the question below. 4. What units are used to measure the width of the chamber? __Nano meter (nm)_______ 5. Does the volume go up or go down when you slide it to the right? ___down____, Did the pressure go up or go down? _____up_____; Why? As handle moves to right it creates decrease in the volume of chamber due to reduction in the width of chamber. As a result of this width reduction, pressure exerted by gas molecule is also high because of high collision of gas with container wall. 6. Sliding the handle all the way to the left as far as it will go give information for answering the question below. Did the pressure go up or go down? _____ down ________; Why? As handle moves to left it creates increase in the volume of chamber due to increment in the width of chamber. As a result of this width increment, pressure exerted by gas molecule is also low because of low collision of gas with container wall. 7. By keeping the temperature and the number of particles constant, pressure is recorded for change in the temperature in table 6. In the analysis following are the parameters Independent variable is: _____Volume____________ Dependent Variable: ________Pressure____________ Constants: ______ Temperature of container and the number of particles _______ Describe the graph and relationship: The volume and pressure have inverse or indirect relation at constant number of particles and constant temperature with each other. From figure 6 it can be seen with increase in the volume, pressure in the container is going to be decrease and this decrease is a little curve with inverse relation. Table 6: Volume (nm3 ) Pressure (atm) 5.0 11.7 7.0 8.30 10 5.90 13 4.50 15 3.90 Figure 6. Relation between Pressure and Volume at constant temperature Experiment 3 – Pressure 1. By giving one pump of light gas particles into the chamber and choosing to hold the Pressure constant by selecting option in the upper right-hand corner. 2. The initial temperature (in K) in the chamber was 300 K. 3. Using the slider at the bottom of the simulator to add heat and increasing the temperature give information for answering the question below. Did the volume go up or go down? _____up________ 4. By keeping the pressure and the number of particles constant, volume is recorded for change in the temperature in table 7. For volume it is assumed that container have height and depth of unity. In the analysis following are the parameters Independent variable is: _____ Temperature ____________ Dependent Variable: ________ Volume____________ Constants: ______ Pressure of container and the number of particles _______ Table 6: Temperature (K) Volume (nm 3) 250 8.30 300 10.0 350 11.7 400 13.3 450 15.0 Figure 7. Relation between temperature and Volume at constant Pressure Describe the graph and relationship: The temperature and volume have direct relation at constant number of particles and constant pressure with each other. From figure 7 it can be seen with increase in the temperature, volume of the container is going to be increase and this increase is linear with direct relation. Analysis Experiment 1: When temperature went ___ _____, the pressure went ____ _____. Possible reason? The pressure in the container is due to collision of particles with the wall of container. As temperature increases it increases the collision of particle with the container hence, pressure increases as temperature increase. Real world example? Some real-life examples of constant volume process are the rupture of a pressure cooker, an aerosol can, and a tire. Experiment 2: When volume went ___ _____, the pressure went ____ _____. Possible reason? The pressure in the container is due to collision of particles with the wall of container. When volume of container increase by keeping number of particles same within it, time taken by the particle for collision becomes higher as compare to low volume of container. Hence, pressure decreases as volume increases. Real world example? Expansion of an air bubble, A hand bicycle pump and medical syringe are the real-world examples for constant temperature process. Experiment 3: When temperature went ____ ____, the volume went ____ _____. Possible reason? Due to exitance of direct relation between temperature and volume increase in temperature causes increase in volume. Real world example? Ping-pong or table tennis is the real-world example for constant temperature process. A common problem with ping-pong balls is they can get a dent when expose to a strong blow or pressure. A common method to fix this dented ball is to immerse the ball into warm water. On immersion, the temperature of the air inside the ball increases and the air expands. The ball is inflated and dents are fixed.