amount of a substance Flashcards
what group 1 metals form
1+ ions
what do group 2 metals form
2+ ions
what does aluminium form
Al3+ ion
what does silver form
Ag+
what does zinc form
Zn2+
what do ions end in
-ide
ammonium nitrate
NH4+ & NO3-
NH4NO3
lithium sulfide
Li+ & S2-
= Li2S
aluminium oxide
Al3+ & O2-
= Al2O3
magnesium hydroxide
Mg2+ & OH-
= Mg(OH)2
calcium nitrate
Ca2+ NO3-
= Ca(NO3)2
what does abundance tell us
how common each isotope is
what do two main peaks of a mass spectrum graph show
shows elements main isotopes
(2 peaks = 2 main isotopes)
what is m/z
relative mass of ion
relative isotopic mass
mass of an atom of as isotope compared with 1/12th the mass of carbon-12
relative isotopic mass
theres 1 relative isotopic mass for each isotope of an element
relative isotopic mass = always a whole number
has no units
relative atomic mass
the average mass of an atom of an element compared to 1/12th the mass of carbon-12
relative atomic mass formula (Ar)
(relative isotopic mass of isotope 1 x % abundance of isotope 1 ) + (relative isotopic mass of isotope 2 x % abundance of isotope 2)
/ 100
molecular formula
tells us the elements in a molecule & number of atoms of each element
e.g Cl —Be —Cl = BeCl2
define empirical formula
simple whole number ratio of the atoms of each element in a compound
relative molecular mass (Mr)
weighted mean mass of a molecule compared with 1/12th the mass of an atom of carbon-12
(work out by adding relative atomic masses)
relative formula mass
same as R.M.M
avogadros constant (NA)
6.022 x 10^23 per mole
[number of particles in one mole of a substance]
amount of substance (n)
number of moles we have of a substance
unit = moles
molar mass (M)
mass of one mole of a substance
g mol-1
amount of substance formula
amount of substance = mass (g) / molar mass (g/mol)
number of particles formula
no. of particles = amount of substance (mol) X avogadro constant
[ first find amount of substance using mass / molar mass
then times by avogadro constant]
volume of gas (dm3)
= amount of gas (mol) x 24.0
ideal gas equation
pV=nRT
p = pressure (Pa)
V = volume (m3)
n = amount of substance (mol)
R = ideal gas constant
T = temp (K)
kilopascals —> pascals = x1000
dm3 —> m3 = /1000
cm3 —m3 = /1,000,000
degrees —> kelvin = +273
