Chapter 10 - Gases Flashcards
What is pressure?
Force divided by area
What are vapors?
The gaseous state of a substance that is normally a solid or liquid.
What is the SI unit for pressure?
Pascal. 1 Pa = 1 N/m^2
How many pascals are in a bar?
10^5 Pa = 1 bar
What is an atmosphere (atm)?
A unit of pressure measurement. 1 ATM = 101325 Pa
What is a torr?
A unit of pressure measurement. 760 torr=1 ATM
What is a barometer?
A tool used to measure atmospheric pressure.
What is a manometer?
A tool used to measure the pressure of enclosed gases.
What is Boyle’s law?
For a constant quantity of gas at constant temperature, the volume of the gas is inversely proportional to the pressure.
P1V1=P2V2
What is Charles’s law?
For a fixed quantity of gas at constant pressure, the volume is directly proportional to its absolute temperature.
V1/T1=V2/T2
What is Avogadro’s hypothesis?
Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
What is Avogadro’s law?
For a gas at constant temperature and pressure, the volume of the gas is directly proportional to the number of moles of gas.
V1/N1=V2/N2
What is the ideal gas equation?
PV=nRT
What does the letter R represent in the ideal gas equation?
The gas constant.
R=.0821 LATM/MOLK
What is the standard temperature and pressure?
0° C and 1 ATM
What is Dalton’s law of partial pressures?
In gas mixtures, the total pressure is the sum of the partial pressures that each gas would exert if it were present alone under the same conditions.
What is a partial pressure?
The partial pressure of a component of a mixture is equal to its mole fraction times the total pressure.
P1=X1P1
X is the mole fraction.
What is a mole fraction?
It is the ratios of the moles of one component of a mixture to the total moles of all components.
What is the kinetic-molecular theory of gases?
It accounts for the properties of an ideal gas in terms of a set of statements about the nature of gases.
These statements are as follows:
-Molecules are in continuous chaotic motion.
-The volume of gas molecules is negligible compared to the volume of their container.
-The gas molecules neither attract nor repel each other.
-The average kinetic energy of the gas molecules is proportional to the absolute temperature and does not change if temperature remains constant.
What is the root-mean-square speed?
It varies in proportion to the square root of the absolute temperature and with the square root of the molar mass.
What is effusion?
When gas molecules escape through a tiny hole.
What is diffusion?
It is the spread of one substance throughout a space or throughout a second substance.
What is a mean free path?
The average distance traveled by molecules between collisions.
Why do real gases depart from ideal behavior?
- The molecules possess finite volume.
2. The molecules experience attractive forces for one another.
What is the van der Waals equation?
It is an equation of state for gases, which modifies the ideal gas equation to account for intrinsic molecular volume and intermolecular forces.
