Question

Select the correct statement.

• A. The order of Xe–F bond length in various fluorides of Xenon is XeF2<XeF4<XeF6
• B. PH5 can undergo sp3d hybridisation to have octahedral geometry.
• C. Dipole moment of CH3F is greater than that of CH3Cl
• D. Increasing strength of hydrogen bonding is Cl–H----Cl< N–H----N < O–H----O < F–H----F

Answer 1

Answer: (D)

Increasing strength of hydrogen bonding is Cl–H----Cl< N–H----N < O–H----O < F–H----F

Answer 2

(1) As $\delta^{+}$ charge on central atom increases, the attraction between $\delta^{+}$ and $\delta^{-}$ increases and thus Xe–F bond length decreases. The correct order is XeF2 > XeF4 > XeF6

(2) PH5 can not undergo sp3d hybridisation as there is much large difference in size of s, p and d orbitals. PH5 does not exist as no partial positive charge develops on P atom.

(3) Dipole moment of CH3Cl is greater than CH3F due to greater charge sepration on carbon and chlorine atoms in CH3Cl.

(4) it is a correct order.

The strength of hydrogen bond depends upon :

(i) size (ii) electronegativity and (iii) ease of donation of electron pair by electronegative element.

Higher the value of electronegativity and smaller the size of the covalently bonded atom to H atom stronger is the hydrogen bonding.