# Shared Flashcard Set

## Details

Exambusters Study Cards 11 Gases
Gases Cards 225-240
20
Chemistry
10/06/2012

Term
 State Normal atmospheric pressure in five standard units
Definition
 1 atm 760 torr 101.3 kilopascals 14.7 lbs/square inch
Term
 definition: Pressure
Definition
 force/area
Term
 barometer
Definition
 An instrument, invented by Torricielli in 1643, which measures atmospheric pressure. An evacuated glass tube in which a column of mercury rises or falls with changing pressure.
Term
 manometer
Definition
 An instrument used to measure pressure of gases in a closed container.
Term
 State three postulates of the Kinetic-Molecular Theory of Gases
Definition
 1. Matter is composed of very small particles; a gas is mostly empty space. 2. Particles are in constant random motion. 3. Collisions are elastic.
Term
 State the formula for Graham's Law of Diffusion.
Definition
 In a mixture of gases A, B:   (RA)(MWA)1/2 = (RB)(MWB)1/2   MW = Molecular Weight R = Rate of diffusion
Term
 Do heavy or light gases diffuse faster?
Definition
 Light gases diffuse faster.
Term
 Charles' Law
Definition
 V1/T1 = V2/T2   Volume and temperature have a direct relationship when pressure and moles of gas remain constant.   V = volume T = Kelvin
Term
 Solve this problem: At 300 K, a gas has a volume of 10 liters. Find the volume at 400 K
Definition
 Use Charles' Law: V1/T1 = V2/T2 V2 = 13.3 L
Term
 Boyle's Law
Definition
 (P1)(V1) = (P2)(V2) Pressure and volume have an inverse relationship when temperature and moles of gas remain constant.   P = Pressure V = Volume
Term
 A sample of gas has a volume of 25 L at 800 torr. Find the volume at 400 torr.
Definition
 Use Boyle's law: (P1)(V1) = (P2)(V2)   V2 = 50 L
Term
 Combined Gas Law
Definition
 P1V1/T1 = P2V2/T2   Moles of gas constant P = Pressure V = Volume T = Kelvin
Term
 Dalton's Law of Partial Pressures
Definition
 In a gas mixture, the total pressure equals the sum of the partial pressures of each component.   Ptotal = P1 + P2 + P3 .....
Term
 Ideal Gas Law
Definition
 PV = nRT   P = Pressure (atmospheres) V = Volume (liters) n = # of moles R = 0.0820 (L atm)/(mol K) T = temperature in K
Term
 How many moles of H2 gas are there in 20 L at 4 atm and 400K?
Definition
 Use the Ideal Gas Law: PV = nRT   n = 2.44 moles
Term
 STP
Definition
 Standard temperature (0 C, 273 K) and standard pressure (1 atm or 760 torr)
Term
 Gay-Lussac's Law of Combining Gas Volumes
Definition
 When only gases are involved in a reaction, the volumes of reactants and products are in a small, whole number ratio.
Term