Question

PHYS 205 Winter 2019 Lab 3 Homework Name:_ 1. You have an air-filled glass jar (height 11 cm), which is tightly closed and attached to a gas pressure sensor (see the photo on the right). The glass jar is initially immersed in a water bath of temperature T-23C n you successively immerse the glass jar in water baths of temperatures T2-rc and T3-98"C and record the gas pressure once it reaches a stable value T-23°C T2 = 1"c T3 = 98°C P,-98.8 kPa P2 = 90.6 kPa P,-122.6 kPa Assume the air in the jar can be modeled as an ideal gas as you answer the following questions: a. Estimate the number of moles of the air in the glass jar. (Hint: estimate the missing data from the photo: what is the general shape of the jar, how does the width compare to the height?). b. Draw three points in a pressure-versus-temperature graph for the equilibrium states reached during the experiment. Based on this graph estimate the temperature of absolute zero (in degrees Celsius)

Answer 1

The height of the jar is approx 4 times the dia of the jar.

Using Universal gas eqn PV =nRT, we find number of moles in each case.

A) n1 = 3.12e-3

n2 = 3.09e-3

n3 = 3.09e-3

B)

But plotting the 3 sets of values, we get the y intercept on the graph which will be the pressure value when the temperature (× coordinate) is 0 degree Celsius.

the pressure value at absolute 0 degree celCels is obtained as, P = 90.27kPa