why is SnCl4 a lewis acid?

SnCl4, FeCl3, FeBr3, etc. are all lewis acids. Remember that the Lewis definition of an acid is that it is an electron pair acceptor. What do all of these previous examples have in common? A metal atom bonded to highly electronegative elements. This will allow the central atom to accept an electron pair as it is left with a large partial positive charge. Any old electrophile will act as a Lewis Acid since electrophiles are seeking electron pairs. Keep in mind that from period 3 and below elements are capable of expanding their octets to accommodate more electrons (as is the case with SnCl4) I hope this helps...On an additional note, the bonds formed to lewis acids will be coordinate-covalent as both of the electrons in the bond are coming from another species.

SnCl4, FeCl3, FeBr3, etc. are all lewis acids. Remember that the Lewis definition of an acid is that it is an electron pair acceptor. What do all of these previous examples have in common? A metal atom bonded to highly electronegative elements. This will allow the central atom to accept an electron pair as it is left with a large partial positive charge. Any old electrophile will act as a Lewis Acid since electrophiles are seeking electron pairs. Keep in mind that from period 3 and below elements are capable of expanding their octets to accommodate more electrons (as is the case with SnCl4) I hope this helps...On an additional note, the bonds formed to lewis acids will be coordinate-covalent as both of the electrons in the bond are coming from another species.

THanks !This is wonderful! You really know your chemistry! How did you about SnCl4? I tried to google and also I looked into my textbook, I didn't find anything!

THanks !This is wonderful! You really know your chemistry! How did you about SnCl4? I tried to google and also I looked into my textbook, I didn't find anything!

Generally any time you see a transition metal bonded to highly electronegative elements (chlorine in this case), you will have a Lewis acid. Good luck with your studies!