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Identify the correct orders against the property mentioned:
A. $\text{H}_2\text{O} > \text{NH}_3 > \text{CHCl}_3$ - dipole moment
B. $\text{XeF}_4 > \text{XeO}_3 > \text{XeF}_2$ – number of lone pairs on central atom
C. $\text{O}-\text{H} > \text{C}-\text{H} > \text{N}-\text{O}$ – bond length
D. $\text{N}_2 > \text{O}_2 > \text{H}_2$ – bond enthalpy
Choose the correct answer from the options given below:
A. $\text{H}_2\text{O} > \text{NH}_3 > \text{CHCl}_3$ - dipole moment
B. $\text{XeF}_4 > \text{XeO}_3 > \text{XeF}_2$ – number of lone pairs on central atom
C. $\text{O}-\text{H} > \text{C}-\text{H} > \text{N}-\text{O}$ – bond length
D. $\text{N}_2 > \text{O}_2 > \text{H}_2$ – bond enthalpy
Choose the correct answer from the options given below:
A
A, D only
B
B, D only
C
A, C only
D
B, C only
Explanation
Dipole moments: $\text{H}_2\text{O} (1.85\text{ D}) > \text{NH}_3 (1.47\text{ D}) > \text{CHCl}_3 (1.04\text{ D})$ (A is true). Bond enthalpies: $\text{N}_2 (946\text{ kJ/mol}) > \text{O}_2 (498\text{ kJ/mol}) > \text{H}_2 (436\text{ kJ/mol})$ (D is true).
Detailed Solution
Analyzing each statement: A. Dipole moment: $\text{H}_2\text{O} (1.85\text{ D}) > \text{NH}_3 (1.47\text{ D}) > \text{CHCl}_3 (1.04\text{ D})$. True. B. Lone pairs on xenon: $\text{XeF}_2$ has 3 lone pairs, $\text{XeF}_4$ has 2, $\text{XeO}_3$ has 1. Correct order is $\text{XeF}_2 > \text{XeF}_4 > \text{XeO}_3$, so B is false. C. Single bond lengths: $\text{N}-\text{O} (\approx 136\text{ pm}) > \text{C}-\text{H} (109\text{ pm}) > \text{O}-\text{H} (96\text{ pm})$, so C is false. D. Bond dissociation enthalpy: $\text{N}\equiv\text{N} (946\text{ kJ/mol}) > \text{O}=\text{O} (498\text{ kJ/mol}) > \text{H}-\text{H} (436\text{ kJ/mol})$. True. Thus, only A and D are correct.