Elements of Group 1 and 2

 The elements in periodic table in which last electron enters in 'S'  orbital of valance shell  are called as 'S'  block elements As this block accommodate only 2 electrons, there are total 2 groups, group first and second belong to the  S  block of periodic table.  Group first elements are called as alkali metals while group second elements are called as alkaline         earth metal except beryllium because their  oxides and  hydroxides are alkaline in nature and they found in earth crust                                               The Electronic configuration of group 1 elements                                            The Electronic configuration...

 Properties of dihydrogen Physical properties : Dihydrogen is colorless, tasteless and odorless gas.  It burns with a pale blue flame. It is a nonpolar water insoluble gas,  lighter than air. Chemical properties :  i. Reaction with metals :     Dihydrogen react with all reactive metal  including alkali metals, calcium, barium at high temperature                                                          ii. Reaction with dioxygen :     Dihydrogen react with Dioxygen to form water in presence of catalyst. This Exothermic reaction  iii. Reaction with halogen :     Hydrogen  react with halogen to  form hydrogen  halides (X= F, Cl, Br, I ) iv. Reducing nature of Dihydrogen :      a) Dihydrogen reduces oxides ...

A. Laboratory Method :  i. Dihydrogen is prepared in laboratory by the action of dilute hydrochloric acid on zinc granules ii. Dihydrogen can be prepared by the action of aqueous solution of sodium hydroxide on zinc                                    B. Industrial methods  i. By electrolysis of pure water: Pure water is a poor conductor of electricity.         Therefore a dilute aqueous solution of acid or alkali is used to prepare dihydrogen by electrolysis        For example, electrolysis of         dilute aqueous solution of sulphuric acid yields two volumes of hydrogen at cathode       and one volume of oxygen at anode. ii. From carbon on hydrocarbon :     Reaction of steam on hydrocarbon at 1270 Kelvin in presence of nickel catalyst gives water gas     ...

Elements of Group 1 & 2  Chemical Equilibrium 

Introduction :  group 1st  and group 2nd are also known as S block elements Group first contain:  hydrogen, lithium, sodium, potassium, rubidium, cesium, francium  Group second contain  : Beryllium, magnesium, calcium, strontium, barium, radium in this chapter we are going to see the p hysical and chemical properties of group first and  second elements step by step first of all we start from hydrogen. Hydrogen :  Hydrogen is the first element in the periodic table. It placed at the top of the group first of  the  alkali metal , but it differs from alkali metal in number of respects and hence it  studied  separately  hydrogen atom consist of nucleus of  +1  charge And one extra nuclear electron,  hydrogen has less  tendency to lose this electron however it bears this one with other electron  to form covalent bond it exists in diatomic form as a H molecule therefore it is called as  dihydrogen...