Chem Wk 14: Properties of Gas, KMT, ATMs, Gas Laws, Gases in Chemical Rxns, Mixtures of Gases, Real Gases
760 760
1 atm = ____ mmHg = ___ torr
mole fraction units 1
1. The partial pressure of each component gas depends only on the component's ___ ___ and the total pressure of the gas mixture. It does not depend on the identity of the component gas or on the other gases in the mixture. 2. Mole fractions have no ___. This means they can be used when describing the behavior of any kind of homogeneous mixture. 3. Finally, the sum of the mole fractions of all the components in a mixture should always add up to __
Volume at STP
22.4 L/mol
Standard Temperature and Pressure (STP)
A temperature of 273 K and a pressure of 1.00 atm
volume pressure
All ideal gases are identical, in terms of their ___ and ____, so it does not matter if one gas is present, or several. The total pressure of a mixture of gases equals the sum of the pressure that each would exert if it were present alone.
molar mass
Although kinetic molecular theory tells us that all populations of gas particles at a given temperature have the same avg kinetic energy, they will not all have the same root-mean-square speed unless they have the same ___ ___
decreases
As M (molar mass) increases, Urms ____.
narrower
As mass increases, Urms decreases As mass increases, speed distribution gets ____.
particles decreases
As mass of gas increases, the # of ____ in a 1g sample ____
closer IMFs smaller
As pressure increases, particles are forced ___ together, so they interact through ___. (Pressure seems ___ than expected)
distribution
As temp increases, we have increased urms, and wider ____ of speeds. urms = square root(3RT/M) where M is molar mass
decreases
As volume increases, density ____.
100 g of gas mixture
Assume __ __ __ ___.
259 mL
At a constant temperature and pressure, the ideal gas law tells us that the volume of 1.00 mol of gas is the same, regardless of its identity. This means that we can compare the volumes of gases the same way we compare moles of gases. It is sometimes easier to measure the volumes of gases rather than their masses in reactions.
densities lower
At a given temperature and pressure, the ____ of gaseous substances are directly proportional to their molar masses and are much ____ than their densities as solids or liquids.
Boyle's law Reference Slide
Boyle's law Reference Slide
Calculating the Quantity of a Gas collected by Water Displacement (pt.1)
Calculating the Quantity of a Gas collected by Water Displacement (pt.1)
Calculating the Quantity of a Gas collected by Water Displacement (pt.2)
Calculating the Quantity of a Gas collected by Water Displacement (pt.2)
Combined Gas Law Example 1
Combined Gas Law Example 1
Combined Gas Law Example 2
Combined Gas Law Example 2
P1V1/n1T1 = P2V2/n2T2
Combined Gas Law Useful Rearrangements: PV=nRT = ____ = _____
Density Exam Type Question
Density Exam Type Question
directly
Density Vs Pressure of an ideal Gas are ____ proportional
Density of a gas reference slide
Density of a gas reference slide
Different Deviations in gases practice
Different Deviations in gases practice
Different gases deviating differently slide
Different gases deviating differently slide
different IMFs Size
Different gases will deviate from ideal behavior in ___ ways: Strength of ___ and the ___ of gas particles will influence this.
Different values of the Universal Gas Constant (R)
Different values of the Universal Gas Constant (R)
own
Each gas in air, or in any other mixture of gases, exerts its ___ pressure
composition
Even though pressure changes, the ___ of the gas does not.
Final Exam Notes
Final Exam Notes
changing
For a problem where there is a change involved, we must manipulate the ideal gas law to fit the given conditions. 1. Determine which variables are ____ and which are held constant
constants same side
For a problem where there is a change involved, we must manipulate the ideal gas law to fit the given conditions. 2. Rearrange the equation so that all the ___ are on the ___ ___ of the equals sign.
Get rid
For a problem where there is a change involved, we must manipulate the ideal gas law to fit the given conditions. 3. ___ ___ of all the constants
given numbers
For a problem where there is a change involved, we must manipulate the ideal gas law to fit the given conditions. 4. Plug the ___ ___ into the equation
Temp. in Kelvin (C + 273.15)
Gas calculations MUST have ___ ___ ___
ideally
Gases are more likely to behave ___ under low pressure and high temperature conditions.
entire
Gases expand to occupy the ____ volume of their containers
Gases in Chemical Rxns example Problem (pt.1)
Gases in Chemical Rxns example Problem (pt.1)
Gases in Chemical Rxns example Problem (pt.2)
Gases in Chemical Rxns example Problem (pt.2)
effuse molar masses smallest
Gases in inflated party balloons escape, or ___ , through the walls of the balloons at rates that are inversely proportional to the ___ ___ of the gases. Those with the ___ molar masses, such as helium, escape the most rapidly.
Ideal gases
Gases that behave in accordance with the combined gas law are called ideal gases
Ideal Gas Law Reference Slide moles K L
Ideal Gas Law Reference Slide: n must be in ___ Temp must be in ___ V in ___
high pressures low intermolecular attractions
Ideal Gas conditions don't hold true under extremely ___ ___ or when subjected to temperatures so ___ that they approach the temperature at which the gases condense. This is because these conditions allow for more _____ _____ to occur
moles volume temperature pressure stoichiometry
In chemical reactions involving a gas as either a reactant or product, the quantity of it (in ___) in the reaction mixture can be determined using the ideal gas law if we know the ___ of the gas and the ____ and ____ at which the reaction proceeds. Once we know the value of n, we can calculate the quantities of the other reactants or products, including the quantity of energy released or consumed, from the ____ of the reaction.
KMT Reference Slide
KMT Reference Slide
negligible no volume
KMT assumptions 1. gas molecules have very tiny volumes compared to the volume they occupy. Individual volumes are considered ____, allowing gas particles to be treated as point masses- masses with essentially ___ ___.
elastic
KMT assumptions 2. Gas molecules move constantly and randomly throughout the space they occupy, continually colliding with one another and their container walls. Collisions considered ____ (result in no net transfer of energy to the walls)
intermolecular
KMT assumptions 3. Because gas particles are so spread out, we assume ____ forces of attraction to one another are negligible. Assume particles don't interact at all
proportional avg. kinetic energy.
KMT assumptions 4. The average kinetic energy of the molecules in a gas is ____ to the absolute temperature of the gas. All populations of gas molecules at the same temperature have the same ___ ___ ___
continuous random
Kinetic Molecular Theory of Gases 1. Gas particles are in ___ ___ motion 2. Volume of gas particles is small relative to total volume in which gas is contained. Distances between particles is large 3. Attractive forces between molecules are zero 4. Collisions between molecules are perfectly elastic. The average kinetic energy is proportional only to temperature.
E=1/2mv^2
Kinetic energy equation
.08206
L*atm/mol*K common value of R
Mole Fraction Reference Slide
Mole Fraction Reference Slide
Mole ratio problems
Mole Ratio Problem
Amontons's Law Equation
P1/T1=P2/T2
Combined gas law
P1V1/T1=P2V2/T2
Boyles law equation
P1V1=P2V2
PV = nRT example 1
PV = nRT example 1
PV = nRT example 2
PV = nRT example 2
PV=nRT Algebra Exam type Question
PV=nRT Algebra Exam type Question
Particle Speed and temperature relationship
Particle Speed and temperature relationship
SW Warm-Up 35; Question 1 Answer 4.38 atm
Pressure Change within a rxn practice problem
inversely directly directly
Pressure and volume are ____ proportional Pressure and Temperature are ____ proportional Volume and Temperature are ____ proportional
less add greater subtract
Pressure is ___ than expected due to IMFs (we ___ in the equation). Volume is ___ than expected due to gas particle size (we ___ in the equation)
volume greater
Real gases have nonzero ____. (Volume seems ____ than expected)
Relative Rates of effusion equation
Relative Rates of effusion equation
Relative Rates of effusion problem
Relative Rates of effusion problem
Temperature
Remember: Average kinetic energy depends only on ____
Rxn Equation Exam Type Problem
Rxn Equation Exam Type Problem
273.15 one ideal 22.4L
Standard Temperature and Pressure: STP: ____ K (0 C)& 1.00 atm At STP, ___ mole of ___ gas occupies a volume of ____
colliding densely pressure
The average distance that a particle can travel through air or any gas before ____ with another one is called the mean free path of the particle. Mean free paths depend on how ____ the air particles are packed, and that depends on their ____.
higher Urms
The average speed of the particles (obtained by adding all the individual speeds and dividing by the total number of particles) is slightly ____ than the most probable speed. Because temperature is proportional to average kinetic energy, and kinetic energy is proportional to the square of speed, it is convenient to define another type of average:the root-mean-square speed. This is the speed of a molecule with average kinetic energy. ____ occurs at a higher speed than either um or uavg.
molar mass 22.4L/mol
The density of any gas at STP can be calculated by dividing its ___ ____ by the molar volume (____)
dipole-dipole stronger greater deviation
The different intermolecular forces experienced by different compounds affect how significantly a particular gas will deviate from ideal behavior under high-pressure and/or low-temperature conditions. For example, polar molecules such as chloromethane (CH3Cl) will experience ___-___ forces that result in attractions between the molecules. These forces are typically ____ than the attractive LDFs experienced by nonpolar molecules such as CH4, and we can predict ___ ____ form ideality for chloromethane than from methane.
spread through another.
The effusion of gases is closely related to their diffusion, which is defined as the ____ of one substance ___ ___
directly
The gas pressure inside a rigid container at constant temperature is ____ proportional to the quantity (number of moles) of gas in the container
temperature pressure 1
The molar volume of an ideal gas takes into account ____ in Kelvin, atm. ____, and number of moles (molar volume assumes ___ mol). Plug this into PV=nRT
abundant partial pressures
The most ___ gases in a mixture have the greatest ___ ___ and contribute the most to the total pressure of the mixture. The mathematical term used to express the abundance of a specific component "i" in a mixture of gases is its mole fraction (xi)
Pi = xiPtotal
The partial pressure of each component is the product of its mole fraction times the total pressure of the mixture.
directly
The pressure of a quantity of gas in a rigid container is ____ proportional to its absolute temperature
Amontons's law (also, Gay-Lussac's law)
The principle that the pressure of a fixed quantity of gas is proportional to its absolute temperature if its volume does not change
Boyle's Law
The principle that the volume of a fixed quantity of gas at constant temperature is inversely proportional to its pressure
Pressure (P)
The ratio of force, F , to surface area, A , defines ___ (_)
inversely
The speed of gas particles at a given temperature are ___ related to their masses.
increasing
The value of both van der Waals constants increase with ____ molar mass and with number of atoms per molecule. Makes sense because larger molecules both take up more space and experience larger LDFs leading to stronger intermolecular forces.
inversely
The volume of a gas is ____ proportional to the pressure we apply.
mole
There are 6.022E^23 gas particles in one ____ of every gas sample.
(3RT/M)^1/2
There is a relationship between the velocity of a gas and its molar mass shown by the equation Urms= ____. Where Urms is the root-mean-square speed of the gas in Meters/second. T is the temperature of the gas in Kelvin. M is the molar mass of the gas in kg/mol.
rxn equation
To determine Pressure and other variables "as reaction proceeds", must always write out ____ ____
high size space increases decreases
Two competing factors-intermolecular forces and the volume of gas-phase particles- can cause PV/RT to decrease or increase with increasing external pressure. At extremely ___ pressures, the ____ of the particles and the ___ they occupy become the dominant factor and PV/RT ___ with increasing P. At less extreme pressures, intermolecular forces may offset the incompressibility of particles and the value of PV/RT ____ with increasing P for some gases, including CH4 and CO2 as shown in figure 9.34
volumes do not masses
Under ideal conditions, the ____ of the individual gas particles are insignificant in comparison to the overall volume occupied by the gas and the particles ___ __ interact with one another. Instead they move independently with speeds that are related to their ____ and to the temperature of the gas.
Charles's Law equation
V1/T1 = V2/T2
Avogadro's Law Equation
V1/n1 = V2/n2
reacts dissolves
Water displacement can be used to collect and measure the volume of any gas that neither ___ with nor ___ appreciably in water.
MP/RT=d
We can use the ideal gas equation to calculate the density of a gas at any temperature and pressure. n/V = P/RT Mn/V=d _____
Weird Partial Pressure Question
Weird Partial Pressure Question
Which equations produce Constants
Which equations produce Constants
Pressure
___ is the amount of force applied to an area
Kinetic Molecular theory of gases (KMT)
a model that explains the behavior of gases on the basis of the motion of the particles that make them up
miscible
all gases are ____ with all other gases - that is, gas mixtures are homogeneous (unless the gases react with each other)
van der Waals equation
an equation describing how the pressure, volume, and temperature of a quantity of a real gas are related; it includes terms that account for the incompressibility of gas particles and interactions between them.
van der Waals forces
any interaction between neutral atoms and molecules, including hydrogen bonds, other dipole-dipole interactions, and London dispersion forces; the term does not apply to interactions involving ions
increasing
atmospheric pressure decreases with ____ altitude. Atmospheric pressure is related to the mass of the column of air above that location. As altitude increases, the mass of the column of air above that altitude decreases. Less mass means a smaller force exerted downward by the air at higher altitude which means less pressure.
Universal gas constant (R)
the constant R in the ideal gas equation; its value and units depend on the units used for the variables in the equation
partial pressure
the contribution to the total pressure made by a component in a mixture of gases. Atmospheric pressure is the sum of the partial pressures of all the gases in the air
Ideal gas equation (ideal gas law)
the principle relating the pressure, volume, number of moles, and temperature of an ideal gas, expressed by the equation PV=nRT where R is the universal gas constant. The value R, however, depends on the units used for pressure and volume (we always express gas in moles and use the Kelvin scale for temperature).
Dalton's Law of partial pressures
the principle that the total pressure of a mixture of gases is the sum of partial pressures of all the gases in a mixture
Charles's Law
the principle that the volume of a fixed quantity of gas at constant pressure is directly proportional to its absolute temperature.
effusion
the process by which a gas escapes from its container through a tiny hole into a region of lower pressure
Avogadro's Law
the prterm-39vinciple that the volume of a gas at constant temperature and pressure is proportional to the quantity (number of moles) of the gas
Graham's law of effusion
the rate of effusion of a gas is inversely proportional M (molar mass)
mole fraction (xi)
the ratio of the number of moles of a particular component "i" in a mixture to the total number of moles in the mixture
average speed.
the root-mean-square speed is a synonym for ___ ___
pressure volume
the van der Waals equation includes two terms to correct for (1) intermolecular forces that lower the number of independent particles and the ___ they create by colliding with the container walls [the a(n/V)^2 term] and (2) the ___ taken up by the particles of a gas, which are not compressible (the nb term)
temp
urms = the speed of a particle with average kinetic energy (will never have to calculate). If ___ is the same, will have the same urms
van der Waals constants practice
van der Waals constants practice
van der Waals constants practice 2
van der Waals constants practice 2
van der Waals constants slide
van der Waals constants slide
