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### Beginner's Guide to Propulsion Reaction of Gases Answers

1. Give one effect the compressibility of air has on an object moving through it.
Above 200 miles per hour, compressibility of air causes drag on the object moving through it.

2. In the Animated Gas Lab, what happens to the volume of a gas when you freeze mass and pressure and increase the temperature?  Why does this happen?
The volume increases.  The volume increase is due to expansion caused by increased heat.

3. When temperature and mass remain constant, what will happen to the pressure when the volume of a gas is decreased? Why?
The pressure will increase, because there is physically less space available for the same amount of gas.

4. Why does an increase in the mass of a gas increase the volume of that gas within the chamber?  (Temperature and pressure remain constant in this example.)
The volume of gas increases because the number of moles is increased.  Similar to water filling a cup, as long as there is space for the water (or gas) to fill up, it will increase in volume.

5. When pressure increases, which variables should remain constant in order to observe an increase in temperature? Mass and volume should remain constant.

6. Explain "Charles and Gay - Lussac's Law."
With the pressure and number of moles held constant in a sample of gas, turning off the burner and allowing the gas to cool will produce a constant ratio of volume to temperature.

7. Following this thinking, if the volume of a given mass of gas is 5 cubic meters, what is the temperature?
If the gas had a volume of 5.0 cubic meters, the temperature would be 375 degrees Kelvin.

8. Which properties depend on the amount of gas in the sample?
Extensive properties depend on the amount of gas.

9. Which formula helps us find the "specific volume" of a gas?
Volume divided by mass finds the "specific volume."

10. Which property of a gas causes pressure within a container?
As the gas molecules collide with the walls of a container, the molecules impart momentum to the walls, producing a force that can be measured.

Related Pages:
Standards
Activity
Worksheet
Propulsion Activity Index
Propulsion Index

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