Gases Flashcards
What is pressure?
The sum of the forces from all the molecular collisions
What is the SI unit for pressure?
Pascal
What is the conversion factor for giga?
10^9
What is the conversion factor for mega?
10^6
What is the conversion factor for kilo?
10^3
What is the conversion factor for centi?
10^-2
What is the conversion factor for milli?
10^-3
What is the conversion factor for micro?
10^-6
What is the conversion factor for nano?
10^-9
What is the conversion factor for pico?
10^-12
What is a barometer? How does it work?
A glass tube where the top is submerged in mercury and atmospheric pressure forces the mercury upwards
What is the formula for atmospheric pressure in a barometer? What do variables stand for?
Patm=ghd
Patm is atmospheric pressure
h is height of liquid column
d is density
g is gravity
How would you convert one bar to pascals?
Multiply by 100 000
How can gas pressure be measured?
Manometer
If height is equal in a manometer what does that mean about the pressure of the gas?
The pressure is the same btwn the atmosphere and gas
If height of side exposed to atmosphere is higher in a manometer what does that mean about the pressure of the gas?
The gas pressure is greater
If height of side exposed to atmosphere is lower in a manometer what does that mean about the pressure of the gas?
The pressure of the gas is less than the atmosphere
What did Boyle’s law find? What is kept constant? What is formula?
Pressure and volume are inversely proportional
Temperature and moles
P1V1=P2V2
What did Charles’s law find? What is kept constant? What is the formula? What unit for temperature is required?
Volume and temperature are directly proportional
Pressure and moles
V1/T1=V2/T2
Kelvin
What does the combined gas law include? What is the formula? What unit must the temperature be in?
Boyle’s and Charles’s law
P1V1/T1=P2V2/T2
Kelvin
What does Avogadro’s Law relate? What stays constant? What is the formula?
Volume is directly proportional to moles of gas
Temperature and pressure
V1/n1=V2/n2
What does the ideal gas law include? What is the formula? What does temperature have to be in?
Boyle’s law, Charle’s law, and Avogadro’s law
PV=nRT
Kelvin
What is one joule equivalent to?
Pam^3 or kpa L
If we know the mass of a gas, what form of the ideal gas law can we use?
PV=(m/M)RT
If we know the density what form of the ideal gas law can we use?
d=PM/RT
If you have the total pressure and the percentage of each gas in the mixture how can you find their partial pressure?
Multiply the percent as a decimal by the total pressure
What is the formula for total pressure?
Ptotal = Pa+Pb+Pc+…
What is the mole fraction?
Moles of one thing/total moles
Which is equal to partial pressure of the thing/total pressure
What is the equation for collecting gases over water?
Ptotal=Pgas+Ph2o
What is the volume of one mole of gas at stp?
22.7 L
How do you find the limiting reagent?
Find moles and divide by coefficients in balanced chemical eqaution
What does the kinetic molecular theory assume?
- The size of gas particle is extremely small (negligible)
- The avg kinetic energy of a particle is proportional to the temperature in Kelvin
- No interaction during collision
What is the formula for the avg kinetic energy of one particle? What do the variables represent?
KE=1/2mu^2
M is mass
U is velocity
What are the units for calculating root mean square velocity?
R- 8.314 j/molK
T- Kelvin
M- kg/mol
What is the variation in speed with molar mass (graph)?
Gases with a lighter molar mass have a distribution that’s shifted toward higher velocity and a broader line
What is the mean free path?
Average distance travelled between collisions
What is effusion?
Gas escapes from container through small hole into a vacuum
What is the difference in the equations for effusion rate and time?
In rate the rate and molar mass of same substance are in numerator and denominated and time the time and molar mass of same substance are in numerator or denominator togehter
What causes gases to not act ideal?
High pressure and low temperatures
