Unit 5: Gas Properties and Reactions

Diffusion

________- transfer of a gas through space over time.

constant T

At ________ and n (Boyles Law)- P and V are inversely proportional so as V decreases, pressure increase.

constant P

At ________ and T (Avogadros law)- V and n are proportional so as volume increases as moles increases.

entire surface

Pressure is a measure of- the total amount of this push (force) exerted by gas molecules hitting the ________ at one instant.

Von der Waals

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

Effusion

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

Boyles Law

________- gases are compressible P1V1= P2V2.

Pb + Pc

Daltons Law- sum of pressures of all different gases in a mixture equals the total pressure Ptot= Pa + ________ +….

Ideal gas assumption

________- often intermolecular forces are essentially negligible, size of the molecules can often be ignored.

Avogadros Law

________- Equal volumes of gases contain same number of moles V1 /n1= V2 /n2.

Amontonss Law

________- Pressure of a gas increases as the temperature of the gas increases P1 /T1= P2 /T2.

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

Boyles Law

gases are compressible P1V1 = P2V2

At constant T and n (Boyles Law)

P and V are inversely proportional so as V decreases, pressure increase

Charless Law

Volume of a gas extrapolates to zero at absolution zero Kelvin V1/T1 = V2/T2

At constant P and n (Charless Law)

V and T are proportional so as T increases, V increases

Avogadros Law

Equal volumes of gases contain same number of moles V1/n1 = V2/n2

At constant P and T (Avogadros law)

V and n are proportional so as volume increases as moles increases

Amontonss Law

Pressure of a gas increases as the temperature of the gas increases P1/T1 = P2/T2

At constant V and n (Amontonss 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

Molecular Weight Determination

Mm = mRT/RV

Density Determination

D = MmP/RT

Daltons 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)