(PMT) Amount of substance Flashcards
What is the symbol for amount
of substance?
n
What is the unit used to
measure amount of
substance?
Mole
What does the Avogadro
constant represent?
The number of atoms per mole of the
carbon-12 isotope
How to calculate the mass of 1
mole of the element?
Mass of 1 mole = relative atomic mass in
grams
How to calculate moles when
mass and molar mass are
given?
Moles (mol) = mass (g) / molar mass or Mr (g mol -1)
State Avogadro’s law
Under the same temperature and
pressure, one mole of any gas would
occupy the same volume.
How much volume does a gas
occupy, at room temperature
and pressure?
24 dm3
or 24000 cm3
Define molar gas volume
The volume per mole of gas molecules
Why do different gas particles
occupy the same volume?
The gas particles are very spread out,
hence individual differences has no
effect.
How to calculate moles when
gas volume is given?
Moles (mol) = volume (dm3 ) / 24 Or Moles (mol) = volume (cm3 ) / 24000
What are the ideal ways in
which gases behave? (5)
● They are in continuous motion
● No intermolecular forces experienced
● Exert pressure when they collide with each other or
container
● No kinetic energy is lost in the collisions
● When temperature increases, kinetic energy of gases also
increase
Write down the ideal gas
equation (in words and
symbols, including the units)
pV = nRT Pressure (Pa) x volume (m3 ) = number of moles (mol) x gas constant (8.314 J mol-1)x temperature (K)
1 atmospheric pressure is
equal to how many pascal?
1 atm = 101325 Pa
0℃ is equal to how many
kelvin?
273 K
What does concentration of a
solution mean?
It is the amount of solute dissolved in 1
dm3
of solvent