(1) In guanidine NH=C(NH2)(NH2), nitrogen labelled as 1 is most basic.
(2) Allyl carbocation is less stable than vinyl carbocation.
(3) +I effect is exhibited by -NH3.
(4) CH2Cl2 is non-polar solvent.
Answer (2)
(1) In guanidine, NH=C(NH_2)(NH_2), the nitrogen labeled as 1 is most basic. This is because this nitrogen atom is part of a structure where resonance delocalization of the lone pair makes it more nucleophilic and hence more basic. The resonance structures help in dispersing the positive charge when protonated, which increases its basicity.
(2) An allyl carbocation is more stable than a vinyl carbocation. The stability of carbocations generally increases with resonance stabilization. An allyl carbocation can be stabilized by resonance since it has adjacent pi bonds that help in delocalizing the positive charge. In contrast, a vinyl carbocation lacks this kind of resonance stabilization because it is directly attached to an sp² hybridized carbon with a double bond.
(3) The +I effect, or positive inductive effect, is exhibited by groups that release electrons through sigma bonds. The -NH_3 group would not exhibit a +I effect as it does not release electrons through sigma bonds in this way. Instead, groups like alkyl groups are known to exhibit a significant +I effect, whereas amino groups generally display more nuanced electronic effects through lone pair donation.
(4) CH_2Cl_2 (dichloromethane) is a polar solvent, not non-polar. It has a polar bond between carbon and chlorine due to the difference in electronegativity between the two elements. The molecule's geometry, being non-linear, ensures there is a net dipole moment, making it a polar compound. Hence, it can dissolve many organic compounds and is often used in extractions.
Guanidine's nitrogen labeled as 1 is most basic due to resonance. The allyl carbocation is more stable than the vinyl carbocation because of resonance stabilization. CH2Cl2 is a polar solvent, not non-polar, due to its polar C-Cl bonds.
;
