Chemstudy

Fajan's rule - Chemical bonding This is the most important theory in chemical bonding and many quastions are solved by understand this theory. According to Lewis theory of bonding there are two types of bond. 1. Covalent bond :                                 In which sharing of electrons take place and covalent compounds having low boiling point and low melting point. 2. Ionic bond :                            In which electron transfer takes place and ionic compounds having high boiling and melting point due to strong electrostatic force between +ve and -ve ions. Let's understand importance of Fajan's rule by taking following example.... NaBr and AlBr3 both are ionic compounds so it should have high melting and boiling point. In case of NaBr M.P. is 747 ℃ but AlBr3 having very low melting poin...

Positive(+ve) and negative(-ve) Inductive groups : -I showing group : NR3+ , SR2+ , NH3+ , NO2- , SO3H , CN-, -CHO, -COCH3, -COOH , -F , -Cl , -Br, -I ,-OR , -OH, Alkyne group , -NH2 ,-CH=CH2 , -H +I showing group : CH2- , NH- , O- , COO- , -C(CH3)3 , -CH(CH3)2 , -CH2CH3 , -CH3 In decreasing order…. You can't called electron withdrawing group as -I effect showing group in all the cases. For example , in case of OH- , it oh group attached with carbon chain it is act as electron withdrawing group but if it is attached with benzene ring it is act as electron donating group.