2 Using the ideal gas law we know that P initial V initia T initia P final V

# 2 using the ideal gas law we know that p initial v

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2. Using the ideal gas law we know that P initial V initia T initia = P final V final T final Equation- 6 For a balloon filled with nitrogen gas starting at low pr pressure (i.e., slightly above atmospheric pressure) we can assume P 1 = P 2 - Charles’s law is applicable . Also, since the balloons used in this experiment are cylindrical (with volume given by ! r balloon 2 h balloon ) we can write Equation 6 as P initial ! r balloon 2 h bal _ initial T initial = P final ! r balloon 2 h bal _ final T final or h bal _ initial T initial = h bal _ final T final Equation 7 Using Equation 7 and a starting and final height as determined (or given) in lab calculate temperature of liquid nitrogen (convert temperature to Kelvin.) give the results assuming 10% uncertainty. 3. Since volume of a gas approaches zero as the temperature of the gas approaches absolute zero, if volume vs. temperature is plotted, the x intercept (i.e., temperature) is absolute zero. Plot height of balloon for room temperature and the height of the balloon at the boiling point of liquid
nitrogen (using true value). Use x intercept to determine absolute zero. 4. From part 3 plot mass vs. one over height (i.e., 1/height) and perform a linear fit. How well does your data support Equation 1 (i.e., is your plot linear and is PV = constant for your data?) Do you think that the assumption that the compression is isothermal is a valid assumption? Why or Why not. 5. Using example 21.3 on page 608 of text (Serway & Jewett) as a guide, calculate both the final pressure and final temperature in part 2 (Adiabatic compression) . To simplify calculations assume V initial V final = H initial H final . Also, assume starting temperature was 22 degrees Celsius (if you did not measure). 6. The volume of the green army tank is approximately one cubic foot . Using the starting pressure (~100 psi) and the ideal gas law PV = nRT compare the left hand side of the equation to the right hand side. The easiest way of getting energy of the left hand side is to multiply starting volume times pressure by 144 since 1 lb f in 2 ! 144 in 2 1 ft 2 . This will give you units of lb f - ft = ft - lb f . Show all units of calculations. The number of moles can be determined by changing pounds of air to grams and using the gram molecular mass of air (29 grams/mole). Answer in SI units is Joules. Convert joules to ft-lbs of energy (use 1 joule = 0.7376 ft - lb f ) and compare to the some of the energies given on the following website

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