Quiz on Gases
Problem #1: What is the correct way of explaining how a vacuum cleaner works? (A or B?)
A) The spinning
motor creates a partial vacuum which creates a suction effect and draws
the dirt into the vacuum cleaner.
|Problem #2: One morning your co-workers and you blow up about a hundred balloons with helium. You tie them together and left them all floating near the ceiling. A few hours later you peek through a window to the room and see all of them on the floor. They still look just as inflated as they did when they were blown up (no helium leaked out). You tell the coworkers not to go into the room and for sure do not light a match. The company you work at develops fuel cells. Why did the helium filled balloons fall to the ground?|
on all spray cans will say something like this: "Contents under
pressure. Do not puncture, incinerate, or expose to temperature above 120F.
Heat from sunlight, radiators, stoves, hot water, and other heat sources
could cause container to burst."
Problem 3: Going from 100°F(311K) to 150F(338K) is only a 8% increase of temperature and also only a 8% increase in pressure if the container holds only gas. However, some left over paint in the can will cause the pressure to go much higher. Why is that?
4: 520 gas cylinders containing 300,000 pounds of chlorine gas
was used as a chemical weapon at Ypres, France in 1915. 5,000 soldiers died
and 15,000 injured.
4a) Air weighs 28.8 grams per mole. How many grams per mole does chlorine gas (Cl2) weigh?
4b) Will chlorine gas stay close to the ground or rise up into the air?
4c) How many grams is 300,000 lbs mentioned above, knowing that 1 lb = 454 grams.
4d) How many moles of Cl2 is 300,000 lbs of Cl2? (use grams from 4c).
|Problem 5: On the right is an oxygen concentrator. It takes rooms air and filters out the nitrogen gas leaving pure oxygen gas for a patient to breathe. It starts by taking room air and pressurizing it. The pressurized gas is then passed through filters that let oxygen atoms pass but not nitrogen. Pressure is achieved with a pump. A piston starts 3 inches from the top of the cylinder and ends 1 inch from the top. If the pressure at 3 inches is 15 psi, what is the pressure at 1 inch?|
The results of a basketball game was called into question with allegations of the basketball being filled with a gas other than air. Your task is to investigate. The ideal gas law PV=nRT may help with some rearranging. Divide both sides by n gives PV/n=RT, now divide both sides by PV to get 1/n=RT/PV. Now multiply by both sides by grams to get g/n=gRT/PV.
is grams per mole and that is what the Periodic Table lists for each element
(atomic mass). So the final formula would read:
To calculate you need g,
T, P, & V.
|For students in my CHM130 class, send answers to firstname.lastname@example.org. Use a subject line of "Quiz on Gases"|