Chapter 15 Ideal Gases Flashcards
What is the SI unit for amount of substance?
Mole (mol)
What is the mol?
It is a number of atoms which when you have that number of atoms the mass is equal to the molar mass of that substance in grams.
e.g. 1 Mole of carbon-12 weights 12 grams
How many atoms is 1 mole? what is this number?
6.02x10^23 atoms. This is avagadros constant
What is the kinetic theory of matter?
This is a model to describe the behaviour of atoms or molecules in an ideal gas
What is an ideal gas?
It is a simplification of the way that gasses act but is suitable for simple calculations
What are the 5 assumptions in the kinetic model made to form the ideal gas model?
- The gas contains a very large number of atoms moving in random directions with random speeds
- The atoms or molecules of gas occupy a negligible volume compared with the volume of the gas
- The collusions of atoms or molecules with each other and the container wall are perfectly elastic
- The time of collisions between the atoms or molecules is small compared with the time between collision
- Electrostatic forces between atoms or molecules are negligible except during collisions
How do ideal gasses cause pressure?
The atoms / molecules in the gas are always moving and the collision between them an the wall of the container exerts a force on the container. This is pressure
What is the force that is exerted on the wall? why?
It is 2mu/Δt. This is because there is the force that is exerted by the atom on the wall and the force that the wall exerts on the atom. This is because it is an elastic collision
What is the equation for pressure?
p = F / A
What is the relationship between pressure and volume?
pressure ∝ 1 / Volume
What is the relationship between pressure and temperature?
pressure ∝ Temperature
What is the ideal gas law?
pV/T = nR or pV = nRT p = Pressure V = Volume T = Temperature n = Number of moles R = Ideal gas constant
What is the equation to use if conditions are changing from one state to another?
p(init)V(init) / T(init) = p(fin)V(fin) / T(fin)
What is the relationship pV / T = nR called?
It is the equation of state of an ideal gas.
What is the molar gas constant? what is its units?
8.31 JK^-1mol^-1