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Grade 9Physical Chemistry

How can we determine by seeing the formula of compound that the compound is electron deficient?? For example BCl3 is electron deficient complete How this compound is electron deficient

Profile image of Asma
7 Years agoGrade 9
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1 Answer

Profile image of Tony
7 Years ago
It is difficult to determine the compound is electron deficient by just seeing its formula .
But you csn very easily explain it with its structure.
Example, 
In BCl3, boron is forming 3 bonds with cholrine atoms. Boron has 3 electrons in its outermost shell. So it will have no lone pairs after forming the bond!
Hence,after BCl3 is formed, Boron has 6 shared electrons (3 of its own and 3 of cholrine). But according to octet theory, it should have 8 electrons for being stable. So, Boron here has a deficiency of 2 elctrons.
If you can thought a little bit structure of given compound, you can use the above way to recognise compounds as electron deficient or electron rich!
I hope it helps you! Approve if you like my answer!