Gas Law And Mole Flashcards
What’s Boyle’s Law?
For a fixed mass of gas is kept at a constant temperature the volume is inversely proportional to the pressure.
What’s Charles’s law?
For a fixed mass of gas kept at constant pressure, the volume is directly proportional to the absolute temperature.
What’s Gay-lussac’s law?
In reactions between gases, the volumes of the reacting gases and the volume of the products, if gaseous, are in the ratio of small whole numbers (at S.T.P).
The Avogadro’s law?
Equal volumes of all gases at the same temperature and pressure contain equal number of molecules.
Whats an Ideal Gas?
One that obeys the gas laws at all temperatures. (In reality no such gas exists)
What’s Avogadro’s constant?
The number of carbon atoms in exactly 12 grams of the carbon-12 isotopes.
What is a mole?
That amount of a substance that contains Avogadro’s constant number of particles.
What is molar volume?
The volume occupied by a gas. It is equal to 22.4L as STP and about 24L at room temperature.
What is molar mass?
The mass in grams of one mole of a substance.
What is a volatile liquid?
A liquid that is easily vaporised.
What is a gas?
A gas is a substance that has no well defined boundaries but defuses rapidly to fill any container in which it’s placed.
What are the two scales of temperature measurement?
Celsius and Kelvin
How do you convert Celsius to Kelvin?
Add 273.
What is pressure in relation to gases?
The pressure of a gas is the force that the gas exerts on each unit area of its container.
What’s the SI unit for pressure?
Newtons per metres squared (N/m^2)
Whats another name for Newtons per meters squared?
Pascals (Pa)
Whats the measurement of atmospheric pressure?
1 x 10^5 Pa.
Whats the SI unit for volume?
Cubic meter (m^3)
What are the other two, less commonly used units for volume?
- Cubic centimetre (cm^3)
- Cubic litre (dm^3)
Do volumes of gases stay the same when temperature and pressure changes?
No, they change.
What are the measurements of STP?
- 273K
- 1x10^5Pa
Whats the Combined Gas Law Equation
P1V1/T1=P2V2/T2
Whats the equation for Boyle’s law?
PV = K
Whats the equation for Charles’s law?
V/T = K
Whats the equation for Ideal gas law?
PV=nRT
Whats the equation for combined gas law?
P1V1/T1 = P2V2/T2 = K
Who developed the kinetic theory of gases?
James Clerk Maxwell and Kidwig Boltzmann.
Give 3 of 5 theory assumptions for the kinetic theory of gases?
- ) Gases are made up of particles whose diameters are negligible compared to the distances between them.
- ) There are no attractive or repulsive forces between these particles.
- ) The particles are in constant rapid random motion, colliding with each other and with walls of the container.
- ) The average kinetic energy of the particles is proportional to the Kelvin temperature.
- ) All collisions are perfectly elastic.
What is the limitation to assumption two? (There are no attractive or repulsive forces between these particles)
There are forces of attraction between the particles of gas (e.g. dipole-dipole).
What is the limitation of assumption 2? (The particles are in constant rapid random motion, colliding with each other and with walls of the container.)
It is not valid to say that the total volume of gas is always negligible compared with the space that they occupy.
When do gases deviate from ideal behavior?
High pressures and low temperatures.
What happens under these conditions?
The effect of the inter-molecular forces become more significant and the volume of the particles cannot be ignored compared to the volume in which they move.
When do gases behave most ideally?
low pressure and high temperature.
Give two reasons of why real gases deviate?
- Inter-molecular forces are present.
- Molecules have volume.
- Collisions are not perfectly elastic.
What is the unit that is used for measuring Gas constant?
JK^-1 mol^-1
How many particles are in a mole?
6.02 x 10^23
Do all moles weigh the same?
No, moles of different substances have different masses.
