321.

The increasing order of O - N - O bond angle in the species NO₂, NO₂⁺ and NO₂^- is

• NO₂^- < NO₂ < NO₂⁺

• NO₂ < NO₂^- < NO₂⁺

• NO₂⁺ < NO₂^- < NO₂

• NO₂ < NO₂⁺ < NO₂^-

For BCl₃, AlCl₃ and GaCl₃ the increasing order of ionic character is

• BCl₃ < AlCl₃ < GaCl₃

• GaCl₃ < AlCl₃ < BCl₃

• BCl₃ < GaCl₃ < AlCl₃

• AlCl₃ < BCl₃ < GaCl₃

The paramagnetic behaviour of B₂ is due to the presence of

• two unpaired electrons in ${\mathrm{\pi }}_{\mathrm{b}}$ MO

• two unpaired electrons in $\stackrel{*}{\mathrm{\pi }}$ MO

• two unpaired electrons in $\stackrel{*}{\mathrm{\sigma }}$ MO

• two unpaired electrons in ${\mathrm{\sigma }}_{\mathrm{b}}$ MO

CO is practically non-polar since

• the $\mathrm{\sigma }$-electron drift from C to O is almost nullified by the $\mathrm{\pi }$-electron drift from O to C

• the $\mathrm{\sigma }$-electron drift from O to C is almost nullified by the $\mathrm{\pi }$-electron drift from C to O

• the bond moment is low

• there is a triple bond between C and O

The state of hybridization of the central atom and the number of lone pairs over the central atom in POCl₃ are

• sp,0

• sp², 0

• sp³, 0

• dsp², 1

Which one of the following is paramagnetic?

• N₂

• NO

• CO

• O₃

The sp³d² hybridisation of central atom of a molecule would lead to

• square planar geometry

• tetrahedral geometry

• trigonal bipyramidal geometry

• octahedral geometry

Hybridisation of C₂ and C₃ of H₃C-CH=C-CH₃ are

• sp, sp³

• sp², sp

• sp², sp²

• sp, sp

Nitrogen forms stable N₂ molecule, but phosphorus is converted to P₄ from P₂ because

• $\mathrm{p\pi }-\mathrm{p\pi }$ bonding is strong in phosphorus 

• $\mathrm{p\pi }-\mathrm{p\pi }$  bonding is weak in phosphorus 

• double bond is present in phosphorus

• single P-P bond is weaker than N-N bond

Which of the following ion is diamagnetic?

• Nd³⁺

• La³⁺

• Tb³⁺

• Er³⁺