Quiz 1 (10 pts)
Chemistry 161 – Dr. Price Name __________________________
PV=nRT R=0.0821 Latm/molK
1. (2.5 points) The mercury barometer below is on a mountain (0.660 atm). Label all
the arrows. Draw on the figure below how the barometer would change and
estimate the pressure reading (in mmHg) if the barometer were brought down to sea
level.
Barometer reading on the mountain (in mmHg) = _____________
Estimated Barometer reading at sea level (in mmHg) = ____________
2. (2 points) Does the volume of 1 mole of an ideal gas increase (I) or decrease (D)
with the following changes (circle the correct answer)?
a. Pressure is reduced by a factor of four at constant T. I D
b. The absolute temperature is decreased by a factor of 3 at constant P. I D
3. (3 points) A 93.0 L sample of dry air cools from 145°C to -22°C while the pressure
is maintained at 2.88 atm.
a. What is the final volume, once it has cooled to -22°C?
b. How many moles of gas are in the balloon?
c. What is the mass of the balloon if the molar mass of dry air is 29.0 g/mol.
4. (2.5 points) For the sample gas mixture pictured below, ,
, and shapes
represent individual gas molecules. Answer the following.
i. What is the mole fraction of ?__________
ii. Which gas has the highest partial
pressure?_______
iii. Which gas has the lowest partial
pressure?______
iv. If the total pressure is 0.75 atm, what is the
partial pressure for ?____________
v.
Would removing all the ‘s change or not
change the partial pressures of the remaining
gases? Explain.
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