I. \(\text{AlCl}_3\)
II. \(\text{NH}_3\)
III. \(\text{BF}_3\)
IV. \(\text{FeCl}_3\)
How many of the above are Lewis acids?
Identifying Lewis Acids Among Given Compounds
A Lewis acid is defined as a chemical species capable of accepting an electron pair. We analyze each compound based on this definition:
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I. \(\text{AlCl}_3\) (Aluminum Chloride):
In \(\text{AlCl}_3\), the central Aluminum atom has only 6 valence electrons, leaving it with an incomplete octet. This electron deficiency allows it to accept an electron pair, making it a Lewis acid.
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II. \(\text{NH}_3\) (Ammonia):
The Nitrogen atom in \(\text{NH}_3\) possesses a lone pair of electrons. This lone pair can be donated to form a coordinate bond. Therefore, \(\text{NH}_3\) acts as a Lewis base, not a Lewis acid.
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III. \(\text{BF}_3\) (Boron Trifluoride):
Similar to \(\text{AlCl}_3\), the Boron atom in \(\text{BF}_3\) has an incomplete octet with only 6 valence electrons. It readily accepts an electron pair, qualifying it as a Lewis acid.
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IV. \(\text{FeCl}_3\) (Iron(III) Chloride):
The Iron(III) ion (\(\text{Fe}^{3+}\)) is a metal cation with a significant positive charge. Such cations are electron-deficient and act as Lewis acids by accepting electron pairs.
Based on the analysis, the Lewis acids are \(\text{AlCl}_3\), \(\text{BF}_3\), and \(\text{FeCl}_3\). There are three Lewis acids among the given options.
Important Questions from Chemical Bonding
The element having which of the following electronic configuration will have highest ionization energy?
Which of the following is true about interhalogen compounds?
In Co-ordinate bond, the acceptor atoms must essentially contain in its valency shell an orbital:
The geometrical shape of PCl5 molecules is
Which of the following molecules has T-shaped geometry?
