calculations Flashcards
moles
mass/mr
PV
nRT
R value
8.31
concentration
moles/volume
degrees to celcius
add 273
cm3 to dm3
/1000
cm3 to m3
/1000000
dm3 to m3
/1000
avogadros constant
6.022 x 10(23)
number or particles
moles of substance x avogadro
density
mass/volume
empirical formulae method
1) divide each mass by atomic mass
2) divide each step 1 answer by smallest step 1 answer
3) multiply step2 to give whole numbers
mass concentration unit
gdm-3
nee diluted concentration
original conc x (original vol/ nee diluted vol)
percentage yield
actual yield/ theoretical yield x 100
percentage atom economy
mass of used products/ mass of all reactants x 100
time of flight
d x square root of (mass/2KE
KE
1/2 mass x volume squared
relative atomic mass
isotonic mass off each x % abundance/ 100
or
isotopic mass of each x relative abundance/ total relative abundance
molar mass
mass/number of moles
concentration of solution
number of moles of solute/ volume of solution
kc
products/reactants
ICE
initial value
change
equilibrium
energy change in calorimetry method
mass of solution x heat capacity(Jg-1K-1) x temp change
enthalpy change of reaction method
1) energy change
2) moles of reactants
3) divide energy change by moles of reactant not in excess to give delta H
4) add sign and unit
delta h reaction of formation
products-reactants
delta h of reaction for combustion
reactants - products
delta h in general
bond energies broken - bond energies made
