Exercises 477(d) If a sample of gas is cooled from 1000.°C to 200.°C,
the volume will decrease by a factor of 5.
(e) If a sample of gas is heated from 473°C to 1219°C,
the volume will increase by a factor of 2.
0 *26.The device shown here is a gas thermometer. (a) At the
ice point, the gas volume is 1.400 L. What would be the
new volume if the gas temperature were raised from the
ice point to 8.0°C? (b) Assume the cross-sectional area of
the graduated arm is 1.0 cm^2. What would be the differ-
ence in height if the gas temperature changed from 0°C
to 8.0°C? (c) What modifications could be made to
increase the sensitivity of the thermometer?*033.A 247-mL sample of a gas exerts a pressure of 3.13 atm
at 16.0°C. What volume would it occupy at 100.°C and
1.00 atm?
*034.Show how Boyle’s and Charles’s gas laws can be obtained
from the combined gas law equation.STP, Standard Molar Volume, and Gas Densities
*035.How many molecules of an ideal gas are contained in a
2.00-L flask at STP?
*036.(a) What is Avogadro’s Law? What does it mean?
(b) What does “standard molar volume” mean? (c) Are
there conditions other than STP at which 1 mole of an
ideal gas would occupy 22.4 L? Explain.
*037.Sodium vapor has been detected recently as a major com-
ponent of the thin atmosphere of Mercury using a
ground-based telescope and a spectrometer. Its concen-
tration is estimated to be about 1.0 105 atoms per cm^3.
(a) Express this in moles per liter. (b) The maximum tem-
perature of the atmosphere was measured by Mariner 10
to be about 970.°C. What is the approximate partial pres-
sure of sodium vapor at that temperature?*027.A weather balloon is filled to the volume of 150. L on a
day when the temperature is 19°C. If no gases escaped,
what would be the volume of the weather balloon after it
rises to an altitude where the temperature is 8°C?
*028.Calculate the volume of an ideal gas at the temperatures
of dry ice (78.5°C), liquid N 2 (195.8°C), and liquid
He (268.9°C) if it occupies 5.00 L at 25.0°C. Assume
constant pressure. Plot your results, and extrapolate to
zero volume. At what temperature would zero volume be
theoretically reached?The Combined Gas Law
*029.Classify the relationship between the variables (a) Pand
V, (b) Vand T, and (c) Pand Tas either (i) directly
proportional or (ii) inversely proportional.
*030.Prepare sketches of plots of (a) Pvs. V, (b) Pvs. 1/V,
(c) Vvs. T, and (d) Pvs. Tfor an ideal gas.
*031.A sample of gas occupies 400. mL at STP. Under what
pressure would this sample occupy 200. mL if the tem-
perature were increased to 819°C?
*032.A 280.-mL sample of neon exerts a pressure of 660. torr
at 26°C. At what temperature in °C would it exert a pres-
sure of 940. torr in a volume of 440. mL?Temperature
scaleLeveling
bulb (adjust
height until
the liquid
levels are
equal)*038.The limit of sensitivity for the analysis of carbon monox-
ide, CO, in air is 1 ppb (ppbparts per billion) by
volume. What is the smallest number of CO molecules
that can be detected in 10. L of air at STP?
*039.A lab instructor asked a student to calculate the number
of moles of gas contained in a 320.-mL bulb in the lab-
oratory. The student determined that the pressure and
temperature of the gas were 732 torr and 23.3°C. The
student calculated the following:_?_mol0.320 L0.0143 molWas the student correct? Why?
*040.Ethylene dibromide (EDB) was formerly used as a fumi-
gant for fruits and grains, but now it is banned because
it is a potential health hazard. EDB is a liquid that boils
at 109°C. Its molecular weight is 188 g/mol. Calculate
the density of its vapor at 180°C and 1.00 atm.1 mol
22.4 LThe surface of the planet Mercury.