how to work out moles from number of particles

number of particles you have/number of particles in a mole

how to work out moles from mass

mass/mR

how to work out moles from concentration and volume

concentration * volume/1000
(/1000 to get from cm to dm)

what is empirical formula

smallest ratio of atoms in each element

how to work out empirical formula from mass

find moles, then divide each by smallest number, then round up into ratio

how to work out empirical formula from percentages

treat the percentage as mass (out of a 100g compound)

how to work out molecular formula from empirical formula

multiply the numbers by the mR

how to write an ionic equation

break up each element into its charged particles, rewrite equation including only the atoms that changed. EG:
HNO+NaOG+NaNO+H20
H++NO+NA++OH _ Na++NO+H20
H++OH_H20

how to work out moles from volume

volume in dm (cm/1000) / molar gas volume
molar gas volume = 24dm^3
[or 24000 cm^3]

what is the ideal gas equation

pV = nRT
pressure*volume = moles*8.31*temp
pressure = Pa
volume = m^3
temp = K (c + 273)

name 2 indicators and what they do

methyl orange = from yellow to red when acid added to alkali
phenolphthalein = from red to clear when acid added to alkali

how to do a general titration

place alkali in beaker, add indicator.
pour known solution of acid into burette.
do rough titration then 3 accurate ones.
do finalinitial reading to get titre.
calculate mean titre (concordant results)

how to calculate percentage yield

actual yield/theoretical yield *1000

how to find % atom economy

mass of desired product/ mass of all products *1000


