Test 2: Unit 5 - Unit 8

\n Properties of a gas (6) - atoms in constant random motion, fills the container it occupies, low density, compressible, mixtures are homogenous, fluid

Ideal gas assumption - often intermolecular forces are essentially negligible, size of the molecules can often be ignored

pressure is a measure of - the total amount of this push (force) exerted by gas molecules hitting the entire surface at one instant

Boyle’s Law - gases are compressible P1V1 = P2V2

At constant T and n (Boyle’s Law) - P and V are inversely proportional so as V decreases, pressure increase

Charles’s Law - Volume of a gas extrapolates to zero at absolution zero Kelvin V1/T1 = V2/T2

At constant P and n (Charles’s Law) - V and T are proportional so as T increases, V increases

Avogadro’s Law - Equal volumes of gases contain same number of moles V1/n1 = V2/n2

At constant P and T (Avogadro’s law) - V and n are proportional so as volume increases as moles increases

Amontons’s Law - Pressure of a gas increases as the temperature of the gas increases P1/T1 = P2/T2

At constant V and n (Amontons’s Law) - P and T are proportional so as T increase, P increases

Combined Gas Law - PiVi/Ti = PfVf/Tf

STP (standard temperature and pressure) - 0 degrees C, 273.15 K, 1atm, 22.4L/mol

Ideal gas constant or molar gas constant or universal gas constant (R=) - 0.08206Latm/molK

Ideal Gas Equation - PV = nRT : P in atm, V in liters, n in mols, T in K

Molecular Weight Determination - Mm = mRT/RV

Density Determination - D = MmP/RT

Dalton’s Law - sum of pressures of all different gases in a mixture equals the total pressure Ptot = Pa + Pb + Pc +…

Moles fraction X - a fraction of moles of “A” in the total moles of the mixture Xa = na/ntot = Pa/Ptot

Von der Waals - corrects for the nonideal nature of real gases (P + n^2a/v^2)(V-nb) = nRT

Kinetic-Molecular Theory - the volume of particles is negligible, particles are in constant motion, no inherent attractive or repulsive forces, and the average kinetic energy of particles is proportional to the temperature

Molecular speed (u) equation - u=√(3RT/Mm)

Diffusion - transfer of a gas through space over time

Effusion - transfer of a gas through a membrane or orifice rate of effusion is proportional to 1/√(Mm)

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The energy of a system is - its capacity to do work

Work - is done to achieve motion against an opposing force

Work= - (Force)(Distance)

When a system changes energy as a result of a difference in temperature between the system and surroundings ___ is exchanged - heat

Thermal motion - disorderly motion

Exothermic Process - a chemical reaction or physical change in which heat is evolved (q