Measuring gases Flashcards
gas
a state of matter with no fixed shape or volume and which fills the space avaliable
properties of gas
low density, unfixed volume and shape, easily compressable, mix readily with other gases
ideal gas
a substance assumed to be composed of molecules of negligable volume and with no intermolecular interactions of exchange of energy when a collision occurs
pressure
the force exerted by on the walls of the container enclosing it
what is pressure reliant on
the temperatue, volume and mole of the gas, the molar mass of the gas does not effect pressutre
mmHg
millimetres of Hg (mercury)
Kpa
kiloppascals
pa
pascals
atm
atmospheres of pressutre
100 Kpa is how many atm
0.987
100 Kpa is how many mmHg
750
1 atm is how many Kpa
101.3
absolute zero
the temperature at which the moolecules in a substance have zero kinetic energy, which means that it is not possible to remove any more energy from it
to convert celcius to kelvin
+273
kelvin unit
represented by T, unit is K
equation to calculate pressure/volume/moles/Temp (non-standard conditions)
PV=nRT
PV=nRT worded equation
Pressure (Kpa) x Volume (L) = moles x Universal gas constant (8.31 J/mol/K) x Temperature (K)
what are the standard lab conditions
25°C, 100KPa
SLC stands for
standard lab conditions
molar volume
the amount of volume occupied by 1 mole of any gas at a particular temperature and pressure
Vm
molar volume
equation to find molar volume/volume/moles at SLC
n=V/Vm
n=V/Vm worded equation
moles= Volume of gas (L)/ molar volume at SLC (Lmol-1)
kinetic molar theory
model to explain the properties of a gas based on the behaviour of the particles of teh gas
how do gas particles move
rapidly in random, straight line motion
pressure equation with force and area
Pressure (Nm-2 / 1 Pa) = forrce (N)/area(m2)
partial pressure
the pressure exerted by 1 gas in a mixture if gases
GHG
greenhouse gases
greenhouse gases
gases that have the property of being able to absorb and re-emit infrared radiation
the process of ghg’s absorbing and re-emitting infrared
- infrared radiation hits a molecule of ghg and causes the bonds to vibrate and bend at a greater rate 2. the molecule then re-emits this infrared heat in all directions, with some escaping into space, butless than would have escaped if ghgs werent present 3. this results in some of the suns heat energy becoming trapped in the lower atmosphere
global warming potential
a measure of how mmmuch energy the emissions of 1 ton of gas will absorb over a given period of time, relative to 1 ton of carbon dioxide
the larger the gwp…
the more that the given gas warms the earth coompared to CO2 in a given time period (usually 100 years)
the greenhouse effect
a natural process that warms the earths surface, it allows life to exist on earth (otherwise average temperature would be -18)
how does a greenhouse work
- short wavelenths from the sun have a lot of energy so are strong enough to pass through gllass 2. once the suns radiation touches an object, the short wavelength turns into a long wavelength 3. the long wavelength has less energy and cannot pass back through thr glass
enhanced greenhouse effect
human induced, is a result of burning fossil fuels and clearing of land that has incresed the amount og ghg’s in the atmosphere, hence more heat being trapped
causes of an increase in greenhouse gases
fires and deforestation, industrialisation, agriculture - practices and animal husbandry
how does fires aaand deforestation contribute to imcreased ghg’s
CO2 is released and the removal of trees means less absorbtion of CO2
how does industrialisation cayse increased GHG;s
release of CO2 equivalent chemicals and ohotochemical smog
how does agriculture practices increae GHg
fuels release CO2, fertilisers release N2O
how does animal husbandry (agriculture) contribute to GHG’s
increase in catttle which results in an increase in methane
