Question

3. Rank the Lewis acidity of the following in the order of strongest to weakest Lewis acid: a. AlMe3, PMe, BMes, NMez b. FjSi™, MezSi", (Eto)Sit, H3Si

Answer 1

3. Rank the Lewis oncidity of the following in the order of strongest to weakest . Lewis aced. a. Almen Prez, B Mez, Nrez . b. fzsit, Mez s+ , (ELO), 55+ , H3 spt The Lewis Acidity onder Almez > BMez > Prez > Nimez Storongest- - Weakest- Explanation Al and B. having Vacant, ponbitals then Almez and Bhez are heurs tads . my DalMez Bmez Vacant-p-ombital But Almez is strongest lewis base than Bmez 'Because the electronegativity of 'B' is more than the (Andy 'All also having vacant d-orbitals * Priez and Mez are lewis bases rez strong Base than pues, Then times weak and than pres .

The Lewrs Acidity onder of the Molecules Hy Set > Mesit > F sst yez sit weakest Storongest A on . Hz Sit is strongest Acid than remaining. I The Acidity onder depends upon the groups Si All the molecules central atom as and having tre Change Indicates vocant onbetala H CHE F: Etö- + I group tigroup thgroup and I trgroup and I group group +I groups incorease the electron densety at se atom and decrease the acidic character +M groups also de Gease the Aerdic character. FI groups are strong donating groups

Than I groups CHE > H weak > F weak Strong donating Eto C Strong donating group group' Then The acidity onder Hz S{ + > (CH3), 59+ > Fz 59+ > (fton$pt Strongest ! S jopron; weakest tM group decrease the Acidic character D VI OFT Nyit: :! Eto-sp + Eto=s . DEL