Purification and Characterisation of Organic Compounds

Purification methods

crystallisation, sublimation, distillation (fractional, steam, reduced pressure), chromatography
Chromatography
$R_{f} = \frac{distance moved by the substance}{distance moved by the solvent}$

Carbon and hydrogen
$%$ C $= \frac{12}{44} \times \frac{m _{CO_{2}}}{m} \times 100,$ $%$ H $= \frac{2}{18} \times \frac{m _{H_{2} O}}{m} \times 100$
Dumas (N)
$%$ N $= \frac{28}{22400} \times \frac{V _{N_{2}} ( STP, mL )}{m} \times 100$
Kjeldahl (N)
$%$ N $= \frac{1.4 \times N \times V}{m}$
Carius (halogen, S)
$%$ X $= \frac{at. mass of X}{mol. mass of AgX} \times \frac{m _{AgX}}{m} \times 100;$ $%$ S $= \frac{32}{233} \times \frac{m _{BaSO_{4}}}{m} \times 100$