1predominant elements found in organic compounds:
carbon, hydrogen and oxygen
2common elements:
halogens (chlorine, bromine and iodine), sulfur and phosphorous
3less common ones:
-arsenic, mercury and other metals
4qualitative tests
-are only for elements other than the carbon hydrogen
5Carbon and Hyrdogen
detected qualitatively by heating a mixture of the given substance with dry copper (II) oxide in a glass tube
6presence of carbon dioxide
-indicated by the formation of the white precipitate of two calcium carbonates when the gaseous products are passed through a solution of a lime water.
7presence of hydrogen
-indicated by the formation of droplets of water in the tube
8ferrox paper
-used to test the presence of oxygen -prepared by soaking filter paper in methanol containing equal amount of ferric chloride and ammonium thiocyanate