Chapter 1.1 Gases Flashcards
What is pressure measured in?
pascal, bar or atmosphere
What is 1 Pascal (Pa) equal to?
force/area (N m^-2)
What is 1 bar equivalent to in Pascals?
1 bar = 10^5 Pa = 100 kPa
What is 1 atmosphere equivalent to in Pascals?
101.325 kPa
How do particles of a molecule behave in the solid state?
fixed position with only vibrational motion
When is the force holding a solid together in a lattice strong? When is it weak?
Strong - ionic solids
Weak - inert gases
What is the correlation between interactive forces and melting point for a solid?
stronger interaction = ↑ melting point = more energy to break bonds
What is the correlation between vibrational energy and temperature?
↑ temp = ↑ vibrational energy
When is vibrational energy present in a solid?
ALWAYS - even at absolute zero (0ºK)
When does the melting point of a solid occur?
magnitude of vibrational modes OVERCOME attractive forces = atoms/molecules lose their fixed position and become LIQUID
How do particles behave in a liquid state?
The attraction between atoms or molecules keeps them touching and particles take the shape of the container due to slightly more motion
How does density relate to liquids and solids?
Solids are usually more dense than liquids and sink (besides ice and water)
How do particles behave in gaseous state?
Most mobile state that expands to fill its container
How is the pressure of a gas determined
Collisions of gaseous particles with the walls of the container
What are the assumptions of an IDEAL gas?
The pressure is not too high and temperature is not close to the condensation temperature
What are the assumptions of the ideal gas Law?
- Atoms/molecules of the gas have no volume
- There are no attractive or repulsive forces acting between atoms or molecules of the gas (ping pong balls)
Why is it assumed that gas volume is zero?
volume of atoms/molecules will be very small compared to the total volume of the container (at low pressure)
Why is it assumed that there are no forces acting between the atoms or molecules of the gas?
Non-covalent interactions that normally would turn the gas into a liquid are taken to negligible if the temperature is greater vaporization/condensation
What is BOYLE’S LAW?
At a constant temperature and fixed amount of gas, GAS VOLUME IS INVERSELY PROPORTIONAL TO GAS PRESSURE
What equations are used in terms of Boyles Laws?
P1V1 = P2V2
Since PxV = constant
What is CHARLES’S LAW?
At constant pressure and a fixed amount of gas, GAS VOLUME AND ABSOLUTE KELVIN TEMPERATURE IS DIRECTLY PROPORTIONAL
What equations are used in Charles’s Law?
V1/T1 = V2/T2
Since V1/T1 = constant
How does the equation appear when BOYLE’S and CHARLES’S LAWS are combined?
P1V1/T1 = P2V2/T2
Since PV/T = constant
For a fixed number of moles
What is AVOGADRO’S LAW?
number of molecules of gas is directly proportional to gas volume
At fixed temperature and pressure
What is the equation of Avogadro’s Law?
V1/n1 = V2/n2
Since V/n = constant
What is the ideal gas law?
V = RnT/P
PV = nRT
What is Avogadro’s Number?
of particles in one mole: 6.022 x 10^23
How can Celsius be converted to Kelvin?
+ 273.15
