3.  Gas particles are much smaller than the distance between them We assume the gas particles themselves have virtually no volume  Gas particles do not attract or repel each other Each particle is too far away from the next Gases are free to move within their containers without interference from other particles

4.  Gas particles are in constant, random movement Particles spread out and mix with each other Particles move in straight lines until they collide with each other or with the walls of their container  Collisions are completely elastic No kinetic energy is lost when gas particles collide with each other or with the walls of their container

5.  Mass and velocity are the two factors that determine the kinetic energy of a particle.  All gases have the same average kinetic energy at a given temperature As temperature increases, average kinetic energy increases As temperature decreases, average kinetic energy decreases

6.  Low Density Because of the large amount of empty space between particles, gases have a small amount of mass for their large volume.  Compression and Expansion Because of the large amount of empty space between particles, gas particles can be squeezed closer together so the gas takes up less space. Because gas particles are in constant random movement, gases will take up as much space as they are given.

8.  Fluidity, Diffusion and Effusion Fluidity: Gases can flow and defuse like a liquid Diffusion: when one material moves through another until the concentration of both are equal throughout the mixture. Because of gas particles constant, random movement, gases diffuse easily through one another. Effusion: when a gas escapes through a tiny opening. Because of gas particles constant, random movement, particles escape through even small openings. Rates of Diffusion and Effusion increase due to Increase in temperature Lighter particles

10.  Pressure is force per unit Gas particles exert pressure when they collide with the walls of their container  There are three things that affect the pressure of a gas: 1. Number of particles 2. Volume 3. Temperature

11.  The particles in the earth’s atmosphere exert pressure in all directions called air pressure.  There is less air pressure at high altitudes because there are fewer particles present.

12.  A vacuum is an area where there are few to no particles and therefore little to no pressure.

13.  Barometers are instruments used to measure atmospheric air pressure. Uses mercury because it is a very dense liquid Units are mm Hg

14.  Manometers are used to measure gas pressure in a closed container.

15.  The SI unit for pressure is the pascal. One pascal is equal to the force of one newton per square meter. A kilopascal is 1000 pascals  Atmospheres are also commonly used One atmosphere is equal to the pressure at sea level at 0 ⁰C.  mm Hg are used because barometers and manometers both measure pressure based on how many mm the Hg moved. Torr is the same thing as mm Hg

18.  Dalton found that each gas in a mixture exerts pressure independently of the other gases present.  The pressure exhibited by a single gas is called its partial pressure  Dalton’s Law of Partial Pressures states that the total pressure of a mixture of gases is equal to the sum of the pressures of all the gases in the mixture. P total = P 1 +P 2 +P 3 +…P n

19.  Shows the relationship between volume (V) and pressure (P)  Temperature is constant P 1 V 1 = P 2 V 2

20.  Boyle’s Law – states that volume and pressure are indirectly proportional when temperature is held constant  As one variable increases, the other decreases.  Less space means particles will hit the walls more often producing more pressure

21. Since gas pressure is caused by collisions if the volume is cut in half, the molecules are closer together, so the concentration is doubled, so the number of collisions is doubled, so the pressure is doubled

22. V 1 =.76 L P 1 = 12.5 atm P 2 = ? V 2 =.51 L

23.  Shows the relationship between temperature (T) and volume (V)  Pressure is constant *Temperature must be in Kelvin ⁰C + 273 = K

24.  Charles’ Law – states that volume and temperature are directly proportional when pressure is held constant  As one variable increases, the other variable also increases and vice-versa.  If we increase temperature, the particles are moving around more. So, to keep pressure constant, the volume has to increase.

25. T 1 = 273 K V 1 = 22.4 L T 2 = ? V 2 = 31.0 L

26.  Shows the relationship between pressure (P) and temperature (T)  Volume is constant *Temperature must be in Kelvin ⁰C + 273 = K

27.  Gay-Lussac’s Law – states that pressure and temperature are directly proportional when volume is held constant  As one variable increases, the other variable also increases and vice-versa.  If we increase temperature, the particles are moving around more. So, if volume is held constant, the pressure has to increase.

28. T 1 = 231 K P 1 = 1.3 atm T 2 = 256 K P 2 = ?

30.  When all three variables change (pressure, volume, and temperature), you will need to use the combined gas law.  The combined gas law combines all three of the previous gas laws. *Temperature must be in Kelvin ⁰C + 273 = K

31. V 1 = 225 L P 1 = 0.94 atm T 1 = 25 o C + 273= 298K P 2 = 0.99 atm T 2 = 0 o C + 273= 273K V 2 = ?

32. (0.94)(225) = (0.99)(V 2 ) 298 273 V 2 = 196 L = 2.0 x 10 2 L

33.  Answer= 1.83 atm

35.  Avogadro’s principle states that equal volumes of gases at the same temperature and pressure contain equal numbers of particles. Avogadro’s principle

36.  The molar volume of a gas is the volume 1 mole occupies at 0.00°C and 1.00 atm of pressure.molar volume  0.00°C and 1.00 atm are called standard temperature and pressure (STP).  At STP, 1 mol of gas occupies 22.4 L.

37.  It is called the Ideal Gas Law because it assumes that gases are behaving “ideally” (according to the Kinetic- Molecular Theory) Ideal gas particles occupy a negligible volume and are far enough apart to exert minimal attractive or repulsive forces on each other.

38.  The ideal gas law describes the physical behavior of an ideal gas in terms of pressure (P), volume (V), temperature (T), and amount (n= number of moles).ideal gas law

40. *R is the ideal gas constant! L mol K atm

41. n = ? T = 100 o C 100+273=373 K V = 1.00 L P = 1.50 atm PV = nRT (1.50)(1.00)=n(0.0821)(373) 1.50 = n(30.6233) n = 0.0490 mol

42.  Answer= 180 KPa