131.

Which of the following statements is false?

• H₂  molecule has 1σ bond 

• Acetylene molecule has 3σ bonds and 3Π bonds

• HCl molecule has 1σ bond

• Water molecule has 2σ bonds and two lone pairs

N₂ and O₂ are converted to monopositive cation ${\mathrm{N}}_2^{+}$ and ${\mathrm{O}}_2^{+}$respectively. Which is incorrect?

• In ${\mathrm{N}}_2^{+}$, the N-N bond weakened.

• In ${\mathrm{O}}_2^{+},$ the bond order increases

• In ${\mathrm{O}}_2^{+},$ paramagnetism decreases

• ${\mathrm{N}}_2^{+}$  becomes diamagnetic

A netural molecule XF₃ has a zero dipole moment. The element X is most likely

• chlorine

• boron

• nitrogen

• carbon

The stablest radical among the following is

• C₆H₅ - CH₂ - $\stackrel{.}{\mathrm{C}}$H₂

• CH₃$\stackrel{.}{\mathrm{C}}$H₂

• C₆H₅ - $\stackrel{.}{\mathrm{C}}$H₂-CH₃

• CH₃-$\stackrel{.}{\mathrm{C}}$H-CH₃

All carbon atoms are sp²-hybridised in

• 1, 3-butadiene

• CH₂=C=CH₂

• cyclohexane

• 2-butene

Among the following species, identify the pair having same bond order CN^-, O${}_2^{-}$, NO⁺, CN⁺

• CN^- and O${}_2^{-}$

• O${}_2^{-}$ and NO⁺

• CN^- and NO⁺

• CN^- and CN⁺

The shape of XeF₄ molecule and hybridisation of xenon in it are

• tetrahedral and sp³

• square planar and dsp²

• square planar and sp³d²

• octahedral and sp³d²

Match List-I and List-II and choose the correct matching codes.

• A - 6; B - 4; C - 1; D - 2; E - 3

• A - 2; B - 4; C - 1; D - 6; E - 3

• A - 2; B - 4; C - 1; D - 6; E - 5

• A - 6; B - 4; C - 1; D - 2; E - 5

In which of the following species, all the three types of hybrid carbons are present ?

• CH₂=C=CH₂

• CH₃-CH=CH-CH${}_2^{+}$

• CH₃-C≡C-CH${}_2^{+}$

• CH₃-CH=CH-CH${}_2^{-}$

The incorrect statement/s among the following is/are

I. NCl₅, does not exist while PCl₅, does.

II. Lead prefers to form tetravalent compounds.

III. The three C-O bonds are not equal in the carbonate ion.

IV. Both O⁺₂ and NO are paramagentic

• I, III and IV

• I and IV

• II and III

• I and III