Moles and the Ideal Gas
equation
Objectives
Be able to state that one mole of any
substance contains 6.02 × 1023 particles and
that 6.02 × 1023 mol-1 is the Avogadro
constant NA.
Be able to select and solve problems using
the ideal gas equation expressed as pV =
nRT, where N is the number of atoms and n is
the number of moles.
OUTCOMES
ALL MUST
• Be able to state that one mole of any substance
contains 6.02 × 1023 particles and that 6.02 × 1023
mol-1 is the Avogadro constant NA.
• Be able to state that R is the molar gas constant and
be able to select and use it correctly from a data
book.
MOST SHOULD
• Be able to show that R has the Units J mol-1 K-1.
• Be able to select and solve problems using the ideal
gas equation expressed as pV = nRT, where N is the
number of atoms and n is the number of moles.
The mole
• The mole (symbol: mol) is the SI base unit
that measures an amount of substance. One
mole contains Avogadro's number
(approximately 6.022×1023) things.
• A mole is like "a dozen" in that both are
absolute numbers (having no units) and can
describe any type of elementary object,
although the mole's use is usually limited to
measurement of subatomic, atomic, and
molecular structures.
• A mole is the amount of substance of a
system which contains as many elementary
entities as there are atoms in 0.012 kilogram
(or 12 grams) of carbon-12.
• It is useful because we can take any element
and 1 mole of it will equal its atomic mass in
grams.
n= mass of sample / molar mass of substance
The Ideal Gas Equation
PV = nRT
The gas constant
• R is called the gas constant and has the
value 8.314 Jmol-1K-1
• since R=PV/nT
• an analysis of the units for
• PV/nT ≡ Nm-2 m3 /mol K
≡ Nm/mol K
≡ J mol-1 K-1
OUTCOMES
ALL MUST
• Be able to state that one mole of any substance
contains 6.02 × 1023 particles and that 6.02 × 1023
mol-1 is the Avogadro constant NA.
• Be able to state that R is the molar gas constant and
be able to select and use it correctly from a data
book.
MOST SHOULD
• Be able to show that R has the Units J mol-1 K-1.
• Be able to select and solve problems using the ideal
gas equation expressed as pV = nRT, where N is the
number of atoms and n is the number of moles.