How is energy transition seen as instrument for achieving zero carbon by 2050 #upsc #mains #exam

Symmetrically subsituted epoxides give the same products in both the acid catalysed and base catalyzed ring opening. An unsymmetrical epoxide gives different products under acid catalysed and base catalysed conditions. Under basic contions, the alkoxide ion simply attacks the less hindered carbon atom in an SN^(2) displacement. Under acidic conditions, the alcohol, attacks the protonated epoxide. Structure II and III show that the oxtrane carbon share part of positive charge. The tertiary carbon bear a larger part of positive charge and it is more strongly electrophilic. The bond between teritiary carbon and oxygen is weaker implying a lower transition state energy for attack at the teritary carbon. Attack by the weak nucleophilic is sensitive to the strength of electrophilic is sensitive to the strength of electrophile. Center attack takes place at more electrophilic carbon which is usually the more substituted carbon because it can better support the positive charge.

How many ionisation energies can carbon have?

Nucleophilic substitution reactions generally expressed as Nu^(-) +R-L rarr R-Nu +L^(-) Where Nu^(-) rarr Nucleophile , R-L rarr substrate, L rarr leaving group The best leaving groups are those that become the most stable ions after they depart. since most leaving group leave as a negatibe ion, the best leaving groups are those ions that stabilize a negative charge most effectively. A good leaving group should be (a) electron-withdrawing to polarize the carbon (b) stable once it has left (not a strong base) (c) polaristable to maintain partial bonding with the carbon in the transition state (both S_(N)1 and S_(N)2) . This bonding helps to stabilise the transition state and reduces the activation energy. Among the following which is false statement?

Nucleophilic substitution reactions generally expressed as Nu^(-) +R-L rarr R-Nu +L^(-) Where Nu^(-) rarr Nucleophile , R-L rarr substrate, L rarr leaving group The best leaving groups are those that become the most stable ions after they depart. since most leaving group leave as a negatibe ion, the best leaving groups are those ions that stabilize a negative charge most effectively. A good leaving group should be (a) electron-withdrawing to polarize the carbon (b) stable once it has left (not a strong base) (c) polaristable to maintain partial bonding with the carbon in the transition state (both S_(N)1 and S_(N)2) . This bonding helps to stabilise the transition state and reduces the activation energy. Among the following which is feasible?