71.

Which of the following is correct comparison of the stability of the molecules?

• $\mathrm{CN} < {\mathrm{O}}_2^{+}$

• CN = N₂

• N₂ < O₂

• ${\mathrm{H}}_2^{+} > {\mathrm{He}}_2^{+}$

Dipole moment of HCl = 1.03 D, HI = 0.38 D. Bond length of HCl = 1.3 $\stackrel{°}{\mathrm{A}}$ and HI= 1.6 $\stackrel{°}{\mathrm{{\rm A}}}$.  The ratio of fraction of electric charge, $\mathrm{\delta }$, existing on each atom in HCl and HI is

• 12: 1

• 2.7: 1

• 3.3: 1

• 1: 3.3

SiCl₄ on hydrolysis forms 'X' and HCl Compound 'X' loses water at l000°C and gives 'Y'. Compounds 'X' and 'Y' respectively are

• H₂SiCl₆, SiO₂

• H₄SiO₄, Si

• SiO₂, Si

• H₄SiO₄, SiO₂

In TeCl₄ the central atom tellurium involves :

• sp³ hybridisation 

• sp³d hybridisation 

• sp³d² hybridisation 

• dsp² hybridisation 

A coordiante bond is a dative covalent bond. Which of the below is true?

• Three atom form bond by sharing their electrons

• Two atom form bond by sharing their electrons

• Two atoms form bond and one of them provides both electrons

• Two atoms form bond by sharing electrons obtained from third atom

The number of antibonding electron pairs in ${\mathrm{O}}_2^{2-}$ molecular ion on the basis of molecular orbital theory is

• 2

• 3

• 4

• 5

Which of the following is isostructural with CO₂ ?

• N₂O

• NO₂

• N₂O₅

• NO

Structure of ammonia is

• pyramidal

• tetrahedral

• trigonal

• trigonal pyramidal

Which of the following contains both covalent and ionic bond ?

• CCl₄

• CaCl₂

• NH₄Cl

• H₂O

The bond energy is the energy required to

• dissociate one mole of the substance

• dissociate bond in 1 kg of the substance

• break one mole of similar bonds

• break bonds in one mole of substance