Question

Given below are two statements.
Statement I: HX bond length is higher in HCl than HF.
Statement II: The lowest boiling point in hydride of group 15 element is having covalency 4.

• A. Both statement I and statement II is correct
• B. Both statement I and statement II is incorrect
• C. Statement I is correct but statement II is incorrect
• D. Statement I is incorrect but statement II is correct

Hint:

In the hydrides of group 15 elements, as the atomic number increases, the covalency decreases, and the boiling points also decrease.

Answer 1

The Correct Option is C

Step 1: Statement I analysis.
The bond length of HX is indeed larger in HCl than in HF. This is because, as we move from HF to HCl, the size of the halide ion increases, leading to a longer bond length. Step 2: Statement II analysis.
Statement II is incorrect. The lowest boiling point in hydrides of group 15 elements is observed in the hydride with covalency 3, not 4, as we move down the group. Step 3: Conclusion.
Therefore, Statement I is correct, but Statement II is incorrect. Final Answer: \[ \boxed{\text{Statement I is correct but statement II is incorrect}} \]