Chemistry - GOC Question with Solution | TestHub
The origin of acidity and basicity in organic compound is great interest and provides an extensive comparison. Among hydrocarbons % s character is taken in account while to decide the acidity, in simple aliphatic acids, more the number of alkyl groups, (+I effect) less is the acidity & more the (– I effect) alkyl groups larger the acidity and vice-versa in the case of simple aliphatic bases. (Benzoic acid is more strong than carboxylic acid as benzoate ion is stabilised more by resonance.) Aromatic amines are less basic than aliphatic amine as the electron pair is less available in case of aromatic amines. The presence of solvent also plays a very important role and at times governs the order too.
Among the following compounds the strongest acid is
Options:
Answer:
Solution:
Question Explanation:
Identify the compound with the highest acidity among the given options by comparing the stability of their conjugate bases.
Concept:
Acidity depends on the stability of the conjugate base formed after loss of H⁺.
Greater stability of the conjugate base → stronger acid.
Hybridisation effect: Higher s-character → conjugate base is more stable.
Solution:
In HC≡CH, hydrogen is bonded to an sp-hybridized carbon, which has higher s-character (50%) and holds negative charge more stably after deprotonation.
In NH3 , CH3NH2 , and C₂H₅NH₂, hydrogen is bonded to sp³-hybridized nitrogen, which is less effective in stabilizing negative charge.
Hence, HC≡CH is more acidic than amines.