- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 1 (29.75 KiB) Viewed 71 times
- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 2 (30.24 KiB) Viewed 71 times
- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 3 (42.07 KiB) Viewed 71 times
- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 4 (51.11 KiB) Viewed 71 times
- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 5 (41.98 KiB) Viewed 71 times
- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 6 (31.75 KiB) Viewed 71 times
- A Q1 What Is The Unit Of P How Do We Evaluate P Experimentally Q2 What Is Po Clarify Q3 What Is Measured Versus Wh 7 (32.35 KiB) Viewed 71 times
a Q1. What is the unit of P? How do we evaluate P experimentally? Q2. What is Po clarify? Q3. What is measured versus what, in this experiment? 04 What is the intercept of the line in the P-t graph with t-coordinate? Why do we call TƏ0 K absolute zero?
a When a gas is heated, it tends to expand. But if it is restricted to a fixed volume the expansion manifest in the form of pressure. Therefore, the equation for change in pressure can be expressed in the similar manner as the expansion of solid, ΔΡα ΡΟΔt. AP = BP at (1) Where, ß is coefficient of proportionality, 4P is change in pressure and At is change in temperature in C or 'F. [Please see appendix for why the temperature unit must be in °C or F We can expand equations (1) as,
P-Po = Pobt-to). Where, P. = pressure at initial temperature to and Pis arbitrary pressure at arbitrary temperature t. If we consider initial temperature, to = 0°C, P= Po + Poßt. (2) Absolute Zero: The gas pressure is created by continuous bombardment of gas molecules on the wall of the container. That is, the pressure is created by kinetic energy. But the temperature of a gas is a measure of its internal energy which is different form of kinetic energies (E = nRT). At any point if pressure of a gas is zero it means the gas molecules are completely at rest or they have zero kinetic energy. Zero kinetic energy literally means zero temperature. Therefore, absolute zero is a temperature at which the pressure of a gas is zero.
8. Make sure the electrical wires are in safe distance from the heater. 9. Turn on the electrical heater. Heat moderately! For moderate heating, you need to put the heater nub somewhere in the middle. Don't use maximum power of the heater ever! 10. Run Data Studio software in the computer where the sensors are connected. Choose new experiment. Double click (or drag and drop) graph mode from the left hand side. You can change the pressure range and temperature range according to your data size as data progresses. Example: Pressure 90 kPa to 120 kPa and temperature 20°C to 70°C. 11. The computer will take data automatically and it may take time. As data progresses read rest of the write up. Start writing report. 12. Once you get a nice straight line in the graph stop data studio. Usually you can get a straight line for temperature range 20 °C to 30 °C. Example: if you have started to take data from 25°C you can stop around 50°C to 60°C. 13. Turn off the heater and unnlug it.
14. Disconnect the sensors and computer Interrace. Take on the gas Dub Trom the water and from the stand. Throw the water in the sink. Data Analysis Part 1: 1. Best fit the graph and find x-intercept. You might have to change the range of Pressure and Temperature axes. You need intercept for pressure axis. Therefore, start pressure range from some negative value like-5.OkPa. You need x-intercept which will be close to -273°C. Therefore, choose x-axis from the value smaller than -273°C such as -300°C. 2. Since the absolute zero is a temperature at which pressure of a gas is zero; it happens at the intercept of temperature axis. Find the value of absolute zero from the intercept of temperature axis. At absolute zero, P-0, and the equation (2) turns to be: (3) 3 B 3. Find the value of from slope of the graph and with the help of equation (2) 4. Find the value of absolute zero temperature in °C, according to equation (3). 5. Find the average value of absolute zero from step 2 and 4. The average value should be
Data Analysis Part II: Considering t=-1/°C as zero, you can start a new system of temperature measurement 7, and its relationship with t in °C is given by, T = 1/B+t (4) Here, T -0 for = -1/B °C. Thus, T = 0 or + = -1/B °C is the lowest possible temperature and is called absolute zero temperature. T' is called absolute temperate because of its scientific origin and is measured in Kelvin unit, after Lord Kelvin, who first discovered it. Unlike "C and °F. which are based on assumptions, Kelvin is derived from scientific facts. Hence it is a scientific system. Combining equations (2) and (4) you can get; P = Poßt (5) From perfect gas law equation, PET. (6) Both equations look similar. If we compare them we will find
P = P.BT. (5) 5 From perfect gas law equation, P="T (6) Both equations look similar. If we compare them we will find. R= ⓇPB (7) 7. Find the value of R from equation (7) provided that w/V = 40.89 moles/m' and Po is the pressure at temperature 0°C that you can get from the intercept of pressure axis. 8. You can also find the value of the R from the graph. Since, T=- with "" and "T" will be the same. Hence, + t, the slope of P RR Slope = (8) 9. Find the value of R from equation (8) 10. Find the auerane vahi af frem 7 and