The Properties of Gases

What properties distinguish gases from solids and liquids?

Gasses expand to fill any container. No volume.

What theory explains the behavior of gases with respect to conditions such as temperature and pressure?

Kinetic Molecular Theory (KMT)

What are the five basic assumptions of the kinetic theory about the properties of gasses?

-Gas particles have no volume.

- Particles move in constant, straight line, random motion.

-Collisions are elastic.

-There are no forces of attraction or repulsion between molecules.

-The average kinetic energy is dependent upon temperature.

What characteristics do real gasses have that contradict the assumptions of kinetic molecular theory?

Gases do have volume and they do have forces of attraction.

What conditions are needed for gasses to behave in a nearly ideal manner?

High temperature, low pressure, non polar atoms/molecules, and small particles.

What is true about the compressibility of gasses?

-The large relative distances between gas particles means that there is considerable empty space between them.

-The assumption that gas particles are far apart explains gas compressibility

-Compressibility is a measure of how much the volume of matter decreases under pressure.

What are the 4 variables used to describe the characteristics of a gas?

Volume (L), Temperature (K), Amount of Moles (n), Pressure (atm, kPa)

How is gas pressure produced?

Gas particles press against the walls of the container.

What is the difference between a barometer and a manometer?

A barometer measures atmospheric pressure and a manometer measures the pressure of any gas.

Sentences that correctly describes how gases behave when the temperature increases.

-The average kinetic energy of the gas particles increases as the particles absorb thermal energy

-Faster-moving particles impact the walls of their container with more energy, exerting greater pressure

How are the average kinetic energy of gas particles and their Kelvin temperature related?

Directly proportional, as one increases so does the other

What conditions indicate STP (standard temperature and pressure)?

0 degrees Celcius and 1 atm OR 273 K and 101.325 kPa

What is the SI unit for pressure? What unit is most commonly used in the United States?

SI unit = kPa, US unit = psi

What are the conversion unit factors?

760 torr = 1 atm.

14.7 psi = 1 atm.

760 mmHg = 1 atm.

101.325 kPa = 1 atm.

What is the conversion factor to convert °F to °C?

ºC = (5/9)(ºF - 32)

What is the conversion factor to convert °C to Kelvin?

K = °C + 273