Ch. 11: Gases
Name_______________________ Hr___
Introduction
In this chapter we will focus on a study of gases. Using prior knowledge, draw a molecular view
of a solid, a liquid, and a gas. Explain the amount of movement of the molecules at each state of
matter on the lines below the boxes.
Solid
_________________
Liquid
_________________
Gas
__________________
Air is a mixture of gases. Approximately 78% of the air is composed of nitrogen gas. The next
most abundant gas in the air is oxygen at about 21%. The remaining 1% of gases in the air
include water vapor, argon, carbon dioxide, helium and hydrogen. Draw a molecular view of air.
Be specific and label with key.
How would your molecular view look if it was air on top of a very high mountain?
In this chapter we will discuss relationships among the characteristics of gases such as
pressure, volume, temperature and amount (number of moles) of a gas.
Section 11.1 (Read pp. 341-344)
___________________ of air molecules generate pressure.
Pressure depends on ___________ and _______.
--Ballet dancer: flat feet vs. on toes OR tennis shoes vs. high heels
A device that measures atmospheric
pressure is a ___________________,
invented by an Italian scientist named
________________________.
*Draw a picture of this instrument.
Give an example of a time when you experienced a change in atmospheric pressure:
_______________________________________________________________________
**********At sea level, the average atmospheric pressure = __________mmHg***********
When a meteorologist says that there is a “low” approaching, it means the atmospheric pressure
will ___________________________, often in conjunction with a _____________.
A device called a _______________________ can be used to measure the pressure of an
_________________ gas sample.
Because instruments used for measuring pressure often contain mercury, the most common unit
of measurement is ________________. Four other units of pressure are:
_______________________________________________________________________.
List 4 conversion factors (think factor-label method) that can be used to convert from one unit
of pressure to another. (Use the "Units of Pressure" chart on pg. 344 or another resource)
Using the factor-label method, solve the following problems:
1. Convert 785mmHg to atm.
2. Convert 0.975atm to torr.