180 likes | 332 Views
A.P. Study Guide. Go Lions!. Lauren Crawford Mr. Tebow. What Symbols Mean. R= Gas Constant M = Molarity = M olal freezing point = M olal boiling point K= Kelvin m = Molality m= Mass i = van’t Hoff Factor = O smotic Pressure(not 3.14) r= Rate of Effusion N= Normality
E N D
A.P. Study Guide Go Lions! Lauren Crawford Mr. Tebow
What Symbols Mean • R= Gas Constant • M= Molarity • = Molal freezing point • = Molal boiling point • K= Kelvin • m= Molality • m= Mass • i= van’t Hoff Factor • = Osmotic Pressure(not 3.14) • r= Rate of Effusion • N= Normality • v= Velocity • u= RMS speed • = Change in Fusion • = Change in Vaporization
Characteristics of Gases • Gases are often referred to as vapors • Gases expand to fill their container • Gases are highly compressible • (When Pressure is applied a gases volume decreases.) • Gases form homogenous mixtures with one another regardless of their identities
Pressure • PRESSURE- The force that that moves something in a general direction • PRESSURE can be measured by the equation: • Standard Atmospheric Pressure corresponds to atmospheric pressure at sea level 1 atm = 760 mmHg = 760 torr = 1.0132510⁵ Pa = 101.325 kPa
The Gas Laws • The PRESSURE-Volume Relationship: Boyle’s Law (The volume of a fixed quantity of gas maintained at constant temperature is inversely proportional to the temperature.) • The Temperature-Volume Relationship: Charles’s Law (The volume of a fixed amount of gas maintained at constant PRESSURE is directly proportional to its absolute temperature.) • The Quantity-Volume Relationship: Avogadro’s Law (Equal volumes of gases at the same temperature and PRESSURE contain an equal number of molecules.)
The IDEAL-GAS Equation • The IDEAL-GAS Equation refers to the types of gases that follow all of the gas laws • The IDEAL-GAS Equation is written as where P=PRESSURE, V= Volume, n= Moles of Gas, R= Constant* (depending on what P is measured in) and T= TEMPERATURE(measured in Kelvin (K= °C+273)) *The R Constant is a stabilizing number that is used in the IDEAL-GAS Equation depending on the units that PRESSURE is measured in. atm Gas Constant R is 0.0821 L atm mol torr/ mmHg Gas Constant R is 64.4 torrmol
Molecular EFFUSION and DIFFUSION • u Refers to the RMS Speed or the particle speeds for different gases. • The lighter gas has a higher RMS Speed and the heavier gas has a slower RMs Speed. • The difference of particle speeds have an effect on the RATE OF EFFUSION which is represented by the equation also known as Graham’s Law • . Discovered by Thomas Graham the rate of effusion seems to be inversely proportional to the molar mass of a gas
REAL GASES • IDEAL GASES stick to the gas laws • REAL GASES follow the VAN DER WAAL’s equation • a and b are constants that are unique to the gases.
DIPOLE-DIPOLE FORCES • Neutral polar molecules attract each other when the positive end of one molecule is near the negative end of another • These forces are only effective when polar molecules are very close together.
LONDON DISPERSION FORCES • Intermolecular forces resulting from attractions between induced dipoles.
HYDROGEN BONDING • The special type of intermolecular attraction between the hydrogen atom in a polar bond particularly (H–F, H–O or an H–N) and an unshared pair on a nearby, small, electronegative ion or atom.
PHASE DIAGRAMS • A phase diagram is a way to summarize the way equilibrium can exist between phases of matter. • The Critical Point is the highest point at which the element or compound can exist • The triple point is where the element or compound can exist in all three stages of matter.
HEAT CURVES Gas Vaporization Liquid Melting Solid
VAPOR POINT DEPRESSION • When you add a substance to a solute is reduces the ability for vapor to escape.
BOILING POINT ELEVATION • When you add a substance to a solute the boiling point will either get higher or lower. • ex. so, if then, that gets added to the BP of the solute and the solute with the solvent is that.
FREEZING POINT DEPRESSION • Freezing Point Depression refers to the substances freezing point. If a substance is added to a solute with a freezing point of 0°C and the substance has a freezing point of -4°C the new freezing point becomes -4°C
OSMOTIC PRESSURE • OSMOSIS is the pressure need to push water through a barrier. • When a substance doesn’t have a known osmotic pressure the equation • refers to osmotic pressure it does not mean pi as in 3.14159265…..
Bibliography • Brown LeMay Textbook • The Internet (for pictures)