Chapter 6, Gases

Average Air pressure at sea level with every Unit

This also functions as a coversion between pressure unit because they equal each other 1.) Atmospheres (atm) = 1 atm 2.) Pascals = 101,325 Pa 3.) Pounds per square inch = 14.7 psi 4.) Torr = 760 torr 5.) inches of mercury = 29.92 in Hg

Avogadro's Law

This law relates volume and moles aka the amount of gas particles under CONSTANT temperature AND pressure - Volume is DIRECTLY proportional, V1/n1 = V2/n2 - n = number of moles

Molar Volume

Volume occupied by 1 mole at STP = 22.4 L/mol

Charle's Law

Volume of a gas is directly proportional to it's temperature Under constant pressure V1/T1 = V2/T2 - Increasing volume of gas will increase the temperature of the gas ONLY IF pressure remains the same

Standard Conditions (STP)

When the volume of mole of a gas which is known as and has value of: - Standard Temperature = 273 K = 1 C - Standard Pressure = 1 atm

Kinetic Molecular Theory

a model that assumes that an ideal gas is composed of tiny particles (molecules) in constant motion

Mole Fraction

number of moles of desired gas divided by the total number of moles in the mixture

Root Mean Square speed of molecules

speed of particles in a gas - R = gas constant (in 8.314 [(Kg)(m^2)s^-1)(mole^-1)]) - T = Temperature (in Kelvin) - M = Molar mass of the gas (in Kg/mol)

Diffusion

when particles that are packed together spread out - High concentration ---> Low concentration

How do you solve Molar Volume at STP

1.) use ideal gas law PV = nRT 2.) arrange to solve Volume 3.) Note that T = 273 K & P = 1 atm 4.)

Boyles Law

A principle that describes the INVERSE relationship between the pressure and volume gas at constant temperature At constant temperature and moles of gas: - P1V1 = P1V2 - where P is pressure and V is volume

Effusion

A process by which gas particles pass through a tiny opening

Barometer

Ecuated glass tube, the tip of which is submerged in a pool of mercury

Van der Waal's Equation

Equation made to account for molecular volume and intermolecular forces - a = vander der waal's constant - b = another Waal's constant - these constants are different for each gas

Celsius to Fahrenheit conversion

F = (C x 9/5) + 32

Pressure

Force exerted per unit area - P = F/A - SI Unit = N/m^2 = Pa = Pascal

Vapor Pressure

The partial Pressure of water vapor

What happens when particles collide in kinetic molecular theory?

The particles exchange energy but there is no loss in energy

Partial Pressure

The pressure of a single gas in a mixture of gases

Dalton's Law of Partial Pressures

The total pressure of a gas mixture is the sum of the partial pressures of its individual gases. P_total = (P_a) + (P_b) + (P_c) + ...

Average Kinetic Energy

The Kinetic energy of gas molecules depends on the average mass and velocity. KE = 1/2(N_A)(m)(u)^ - KE = Average Kinetic energy - N_A = Avogadros number (6.022*10^23) - m = mass - u = velocity

Gas Constant (R) value

R = 0.08206 (L*atm)/(Mol*K) - "Liter-atmospheres per Moles-Kelvin"

What are the conditions for a gas to behave ideally

- High Temperature - Low Pressure

Pressure and concentration relationship

- Increasing concentration INCREASES Pressure - increasing Volume (decreasing concentration) DECREASES Pressure

Charle's Law Real life examples

- One reason a helium balloon decends after some time. it cools down which decreases the volume slightly making it denser, but the main reason is helium molecules escaping - Same thing for a hot air balloon expect instead you are heat the air which causes the volume to expand.

Variables used in the ideal gas law

- P = Pressure - V = Volume - n = Number of Moles present (amount) - R = Gas constant - T = Temperature

Partial pressure from Mole fraction

- P_a = Partial pressure of gas in mixture - X_a = Mole fraction of gas in mixture - P_total = total pressure in the mixture

Units of Pressure

- Pascal = Pa = N/m^2 - Pounds per sqaure inch (psi) = lb/in^2 - Torr - Inches of mercury - atomospheres

Graham's Law of Effusion

- Rate 1 & 2 = How fast gases 1 & 2 escapes through tiny hole - M = Molar masses

The Simple Gas Laws

1.) Boyle's Law 2.) Charles's Law 3.) Avogadro's Law 4.) Ideal Gas Law

Three Postulates of Kinetic Molecular Theory

1.) Gas molecules are negligibly small 2.) Average kinetic energy of particle is proportional to temperature in Kelvin 3.) collision of one particle with another (or walls of container) is completely elastic

Boyles Law and diving in water

If you are deep underwater and you rise quickly the air in your lungs will expand due to the pressure increase therefore: - EXHALE when rise from high pressure

Celsius to Kelvin Conversion

K = C + 273

Ideal Gas Law

Law that combines the other three laws together, contains: - Boyle's Law - Charle's Law - Avogadros Law Pv = nRT The conditions of the other gas laws are solved by setting 2 the necessary variable(s) constant

Mean Free Path

average distance particles travel between collisions

Density of a Gas at STP

d = [molar mass]/[molar volume]