Chapter 8 Flashcards
What are gases?
state of matter where atoms of a substance move
freely and fill their container
What are gases in terms of volume and shape?
no fixed volume and shape
What do gases do in containers?
uniformly fill them
Are gases easily compressible?
yes
How do gases mix with other gases?
uniformly mix
What do gases exert for pressure?
Exert pressure on their surroundings
What’s the equation for pressure?
force / area
What are the units for pressure?
atmospheres (atm), mmHg, Torr, Pascal (Pa)
What is atmospheric pressure?
is the force exerted on a surface by the air above it due to gravity
What are the variables associated with gases?
pressure, temperature, volume, moles
What is STP defined as?
standard temperature and pressure as 273.15 K and 1 atm
What is Boyle’s Law?
P1V1 = P2V2
What is constant in Boyle’s Law?
constant temp
What is Gay-Lussac’s Law?
P1/T1 = P2/T2
What is the concept behind Boyle’s Law?
When volume decreases,
pressure increases which mean Particles hit the container walls more often
What is the concept behind Gay-Lussac’s Law?
When temperature increases,
pressure also increases
What is constant in Gay-Lussac’s Law?
constant volume and amount of gas
What is Charle’s Law?
V1/T1 = V2/T2
What is the concept behind Charle’s Law?
when temperature increases,
volume must also increase
What is constant in Charle’s Law?
pressure and amount of gas
What is Avogadro’s Law?
v1/n1 = v2/n2
1 mol of ideal gas =
22.4 L
What is the concept of Avogadro’s Law?
Equal volumes of gas contain the same number of particles at the same temperature and pressure
To have an ideal gas, what must the motion of the particles be?
random
To have an ideal gas, what interactions must the gas particles have?
no interactions except collisions that are elastic
To be an ideal gas, is the identity of the gas relevant or irrelevant?
irrelevant
To be an ideal gas, what has the be the volume of the gas instead of the gas itself?
the volume of the container it occupies
What is the Ideal Gas Law?
P=nRT
In the Ideal Gas Law, what does P equal?
pressure
In the Ideal Gas Law, what does n equal?
moles
In the Ideal Gas Law, what does R equal?
Gas constant
In the Idea Gas Law, what does T equal?
temperature
What is Dalton’s Law of Partial Pressures?
For a mixture of gases in a container, the total pressure
equals the sum of the pressures each gas if it were alone. (p1 + p2 + p3… =p total meaning 2 atm + 7 atm = 9 atm)
What is a mole fraction?
the ratio of the number of moles of a
a component in a mixture to the total number of moles in the mixture
What’s the formula for mole ratio?
X1 = n1 / 𝑛𝑇𝑜𝑡𝑎𝑙
= 𝑛1 /𝑛1+𝑛2+𝑛3+…
What does the Kinetic Molecular Theory state about volume?
Gas particles are so small compared to the distances between them that the volume of the individual particle can be assumed to be negligible or zero
What does the Kinetic Molecular Theory state about motion of gas particles?
Gas particles are in constant motion
What does the Kinetic Molecular Theory state about gas exerting forces on each other?
Gas particles are assumed to exert no forces on each other
What does the Kinetic Molecular Theory state about the relationship between kinetic energy and the temperature of the gas?
they are directionally proportional
What does diffusion describe?
process of particles moving from an area of high concentration to one of low concentration
What does effusion describe?
small size enables them to move through small openings as well
What does there need to be for effusion to happen?
opening of the hole must be smaller than the mean free path because otherwise, the gas could move back and forth through the hole
What does Graham’s law of effusion state?
The rate of effusion of a gas is inversely related to the square root of the molecular weight of a gas
What does Van der Waal’s equation contain?
corrected pressure and volume
In reality, REAL gases behave more ideal in ___ temperature and ___ pressures
In reality, gases behave more ideal in high temperatures and low pressures
What is the urms equation for?
the measure of the speed of particles in a gas
What is Graham’s Law of effusion?
R1/R2 = square root of m2 over square root of m1
