All Students Notes

Question 8:What are conjugated bonds? Answer.   Alternated sigma and pi bonds are called conjugated bonds. Conjugated bonds are only formed if 1. two pi bonds are separated by a single sigma bond and 2.all  adjacent p orbitals are aligned (co-plainer) with each other. On the other hand, conjugated bonds are not formed if there are two or more sigma bonds between two pi bonds or p orbitals of adjacent pi bonds are not co-plainer. In conjugated bonds, pi bonds are close enough to each other to interact across sigma bonds. Due to interaction between two pi bonds, a partial double bond is formed which enables the pi electrons to be delocalized over whole system. Question 9. Why are alkanes more reactive than alkyne? Answer.   Although electron density in alkyne is higher than in alkene, still alkyne are less reactive in electrophilic additions. There are two reason for low reactivity of alkyne. 1. Electronegativity of sp hybridized carbon atoms of triple bond in alk...

Question 1: Why carbon is sp 3 hybridized in most of organic compound? Answer: The term 'sp 3 ' refers to intermixing of one 's'  and three 'p' atomic orbitals of an atom to produce four new hybrid orbitals.  In most of organic compounds, carbon is bonded with four other  atoms through single covalent bonds.  This cannot be achieved by carbon having two electrons in 2p atomic orbital. In order to make four bonds, one electron from '2s' is excited to the '2p: atomic orbital. Thus, carbon becomes tetravalent. However, these four orbitals make similar bonds (equivalent). In order to justify equivalency, it is assumed that carbon undergoes sp 3 hybridization, in which one s and three p atomic orbitals intermix with other to produce four sp 3 hybridized orbitals which have same characteristics. Question 2: How is pi bond formed in alkene and alkyne? Answer. Pi bond in Alkenes: In alkene , carbon atoms bonded twice with each other are sp 2 hyb...