Chlorine has a high electronegativity and a high electron affinity, the latter being even slightly higher than that of fluorine. A jet of hydrogen will burn in chlorine with a silvery flame. Its high affinity for hydrogen allows chlorine to react with many compounds containing hydrogen. Chlorine reacts with hydrocarbons, for example, substituting chlorine atoms for the hydrogen atoms successively. If the hydrocarbon is saturated, however, chlorine atoms readily add to the double or triple bond.
Chlorine reacts with many elements of both metals and nonmetals to give chlorides.
Only toward carbon, nitrogen, and oxygen is it fairly inert. Thus, vanadium forms a pentafluoride, whereas the pentachloride is unknown, and sulfur gives a hexafluoride but no hexachloride. With sulfur, even the tetrachloride is unstable. Chlorine displaces the less electronegative halogens from compounds. Cl 2 7.66H 2 O is obtained.