Question

Increasing order of Lewis acidity of boron halides is.

Answer 1

.this trend is due to pie back bonding. All halides have lone pairs, they donate one lone pair to boron by overlapping with the p orbital of boron. Effective overlap between orbital’s decreases due to large size of p orbital of halides.Hence,electron deficiency of boron atom in its halides follow the trend--BI3>,BBr3,>BCl3>BF3 and so it is the Lewis acidity ORDER .


                                      BI3>BBr3>BCl3>BF3

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