Question

Correct order of basicity of the following is:

• A. E $>$ A $>$ B $>$ C $>$ D
• B. E $<$ A $<$ B $<$ C $<$ D
• C. C $>$ A $>$ B $>$ D $>$ E
• D. E $<$ B $<$ D $<$ A $<$ C

Hint:

Memory aid: C, N, O. On the periodic table, basicity increases as you move left: $R^{-} > NH_{2}^{-} > OH^{-}$.

Answer 1

The Correct Option is B

Step 1: Concept Basicity is the tendency of a species to donate a pair of electrons. It is generally the inverse of the acidity of the conjugate acid.

Step 2: Meaning A weaker acid has a stronger conjugate base.

Step 3: Analysis Consider conjugate acids: $RH$ (alkane) $<$ $NH_{3}$ (ammonia) $<$ $ROH$ (alcohol) $<$ $H_{2}O$ (water) $<$ $H_{3}O^{+}$ (hydronium). Alkanes are the weakest acids, so $R^{-}$ is the strongest base. Water is the strongest "acid" in this list, so $H_{2}O$ itself (neutral) is the weakest base.

Step 4: Conclusion The order of increasing basicity is $H_{2}O$ (E) $<$ $OH^{-}$ (A) $<$ $OR^{-}$ (B) $<$ $NH_{2}^{-}$ (C) $<$ $R^{-}$ (D). This matches option (B). Final Answer: (B)