Which one of the following compounds is NOT considered an acid ?
BF₃
AlCl₃
NH₃
C₆H₅OH
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CAPF – 2015
B) AlCl₃ (Aluminum Chloride) is also a Lewis acid as the Aluminum atom has an incomplete octet and can accept an electron pair.
C) NH₃ (Ammonia) is a Brønsted-Lowry base because it can accept a proton (H⁺) to form ammonium ion (NH₄⁺). It is also a Lewis base because the nitrogen atom has a lone pair of electrons that it can donate. It is not considered an acid in standard definitions.
D) C₆H₅OH (Phenol) is a weak acid because the hydroxyl group (-OH) attached to the benzene ring can donate a proton, forming the phenoxide ion. The acidity is enhanced by the stability of the phenoxide ion through resonance.
Therefore, NH₃ is the compound that is NOT considered an acid; it is a base.