Class 12

Chlorine Occurrence Chlorine is very reactive and does not occur in nature in free state. It occurs mostly as chlorides of sodium and other alkali and alkaline earth metals. The most abundant compound of chlorine is sodium chloride (rock salt) and occurs in extensive evaporite deposits, saline lakes and brines and in the ocean. Other sources of chlorine are sylvine (KCl), … [Read more...] about Chlorine

Chemical Reactivity   The halogens react readily with metals and non-metals to form halides. Fluorine is the most reactive of all the halogens. The reactivity of the halogens decreases down the group.   The high reactivity of halogens is due to the following reasons :   (i) Low dissociation enthalpies All the halogens have very low dissociation enthalpies. As a result, … [Read more...] about Chemical Properties of Group 17 Elements

Group 17 Elements Group 17 of the periodic table contains five elements : fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (At). These are named as halogens. The name halogens is derived from two Greek words halo meaning sea salt and gens meaning born i.e., sea salt produce because the first three members occur as salts (chlorides, bromides and iodides) in … [Read more...] about Physical Properties of Group 17 elements

Oxoacids of Sulphur     Sulphuric Acid   Manufacture of Sulphuric Acid Sulphuric acid can be manufactured by Contact process. The process involves the following steps:   (i) Preparation of sulphur dioxide Sulphur dioxide is prepared by burning sulphur or iron pyrites in excess of air. S+O2 → SO2   4FeS2 + 11O2 → 2Fe2O3 + 8SO2 Iron pyrites   (ii) Oxidation of … [Read more...] about Sulphuric Acid