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Write Lewis Acid-Base principle. |
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Answer» Solution :Defination : G.N. Lewis in 1923 defined an "acid as a species which accepts electron pair and base which donates an electron pair." Comparison of Bronsted-Lowry and Lewis Base: As far as base are concerned, there is not much DIFFERENCE between Bronsted-Lowry and Lewis concept, as the has provides a lone pair in both the cases. The Lewis base `NH_3` donate electron pair to `H^+` and `NH_4^+` is farm. `NH_3` is act as base in both principle. All Lewis base will be Bronsted-Lowry base and Lewis base. Comparison of Bronsted-Lowry and Lewis Acid : In Bronsted-Lowry acid must containing PROTON. HOWEVER, in Lewis concept many acids do not have proton. Electron deficient species like `BF_3 , AlCl_3 , FeCl_3 , NO_2^(+), Mg^(2+) , Co^(3+)`etc. can be act as Lewis acids. "Thus all Lewis acid not act as Bronsted-Lowry acid." `UNDERSET"Lewis acid"(BF_3) + underset"Lewis base"( :NH_3) to F_3F: NH_3` Species like `H_2O , NH_3 , OH^-` etc. which can donate a pair of ELECTRONS can act as Lewis bases. |
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