Question

In which if the following changes there is no change in hybridization of the central atom?

• A. C2H₄ →(H₂NI)C₂H₆
• B. NH₃ + H⁺ → NH^{4 +} 
• C. BF₃ + F^- → BF^4-
• D. PCL₅ + CL^- → PCL^6-

Answer 1

The Correct Option is B

To solve the problem, we need to identify in which chemical change the hybridization of the central atom remains the same before and after the reaction.

1. Analyze Each Option:

• Option A: $C_2H_4 \xrightarrow{H_2/Ni} C_2H_6$
  - In $C_2H_4$, carbon is $sp^2$ hybridized.
  - In $C_2H_6$, carbon is $sp^3$ hybridized.
  Hybridization changes → Incorrect
• Option B: $PCl_5 + Cl^- \rightarrow PCl_6^-$
  - In $PCl_5$, phosphorus is $sp^3d$ hybridized.
  - In $PCl_6^-$, phosphorus is $sp^3d^2$ hybridized.
  Hybridization changes → Incorrect
• Option C: $BF_3 + F^- \rightarrow BF_4^-$
  - In $BF_3$, boron is $sp^2$ hybridized.
  - In $BF_4^-$, boron is $sp^3$ hybridized.
  Hybridization changes → Incorrect
• Option D: $NH_3 + H^+ \rightarrow NH_4^+$
  - In $NH_3$, nitrogen is $sp^3$ hybridized.
  - In $NH_4^+$, nitrogen is still $sp^3$ hybridized (lone pair donates to form a coordinate bond).
  No change in hybridization → Correct

Final Answer:
The reaction $ NH_3 + H^+ \rightarrow NH_4^+ $ shows no change in the hybridization of the central atom.