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“Lewis super-acids”

6th March, 2023

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Context

  • Researchers at the Paderborn University, Germany have reported being able to make a unique class of catalysts – used in chemistry to accelerate reactions – called “Lewis super-acids”.

About “Lewis super-acids”

  • Named for the chemist, G N Lewis, Lewis super-acids derive from Lewis acids.
  • A Lewis acid is any substance, such as a Hydrogen ion (H+) that can accept a pair of nonbonding electrons.
  • In other words, a Lewis acid is an electron-pair acceptor. A Lewis base is any substance, such as the OH- ion, that can donate a pair of nonbonding electrons. A Lewis base is therefore an electron-pair donor.
  • Because Lewis acids add electron pairs, they are often used to speed up chemical reactions.
  • Lewis superacids are stronger than antimony pentafluoride -- the strongest Lewis acid -- and can break even the toughest bonds. Breaking strong, chemical bonds requires highly reactive substances.
  • Because they are so reactive, they are hard to manufacture.
  • Being able to make these super acids, enables non-biodegradable fluorinated hydrocarbons, similar to Teflon, and possibly even climate-damaging greenhouse gases, such as sulphur hexafluoride, to be converted back into sustainable chemicals.

PRACTICE QUESTION

Q) Which of the following statements is/are correct?

a. A Lewis acid is any substance, such as a Hydrogen ion (H+) that can accept a pair of nonbonding electrons.

b. Because Lewis acids add electron pairs, they are often used to speed up chemical reactions.

 I. Only a

II. Only b

III. Both a and b

IV. Neither a nor b

Answer: Option III

 

https://www.thehindu.com/sci-tech/science/what-are-lewis-super-acids/article66566719.ece