The correct arrangement of the species in the decreasing order of the bond length between carbon and oxygen in them is

• CO, CO₂, HCO${}_2^{-}$, CO${}_3^{2-}$

• CO₂,CO, CO${}_3^{2-}$, HCHO${}_2^{-}$

• CO${}_3^{2-}$, HCO${}_2^{-}$, CO₂, CO

• CO, CO${}_3^{2-}$, CO₂, HCO${}_2^{-}$

A correct statement is

• [Co(NH₃)₆]²⁺ is paramagnetic

• [MnBr₄]^2- is tetrahedral

• [CoBr₂(en)₂]^- exhibits linkage isomerism

• [Ni(NH₃)₆]²⁺ is an inner orbital complex

Which one of the following conversion results in the change of hybridisation and geometry?

• CH₄ to C₂H₂

• NH₃ to N⁺H₄

• BF₃ to BF${}_4^{-}$

• H₂O to H₃O⁺

If the bond energies of H-H, Br-Br and H-Br are 433, 192 and 364 kJ mol^-1 respectively, then $∆$H° for the reaction-

H₂ (g) + Br₂ (g) → 2HBr (g) is

• -261 kJ

• +103 kJ

• +261 kJ

• -103 kJ

The shape of XeF₆ is

• square planar

• distorted octahedral

• square pyramidal

• pyramidal

CO is a stronger ligand than Cl^-, because

• CO is a neutral molecule

• CO has $\mathrm{\pi }$-bonds

• CO is poisonous

• CO is more reactive

297.

Which of the following sequence is correct regarding field strength of ligands as per spectrochemical series?

• SCN^- < F^- < CN^- < CO

• F^- < SCN^- < CN^- < CO

• CN^- < F^- < CO < SCN^-

• SCN^- < CO < F^- < CN^-

The increasing order of bond order of O₂, O${}_2^{+}, {\mathrm{O}}_2^{-} \mathrm{and} {\mathrm{O}}_2^{2-}$ is

• ${\mathrm{O}}_2^{+} < {\mathrm{O}}_2 < {\mathrm{O}}_2^{-} < {\mathrm{O}}_2^{2-}$

• ${\mathrm{O}}_2^{2-} < {\mathrm{O}}_2^{-} < {\mathrm{O}}_2^{+} < {\mathrm{O}}_2$

• ${\mathrm{O}}_2 < {\mathrm{O}}_2^{+} < {\mathrm{O}}_2^{-} < {\mathrm{O}}_2^{2-}$

• ${\mathrm{O}}_2^{2-} < {\mathrm{O}}_2^{-} < {\mathrm{O}}_2 < {\mathrm{O}}_2^{+}$

Main axis of diatomic molecule is z. The orbitals p_x and p_y overlap to form

• $\mathrm{\pi }$-molecular orbital

• σ-molecular orbital

• δ-molecular orbital

• No bond is formed

Using MOT, compare ${\mathrm{O}}_2^{+} \mathrm{and} {\mathrm{O}}_2^{-}$ species and choose the inncorrect option.

• ${\mathrm{O}}_2^{+}$ have higher bond order than ${\mathrm{O}}_2^{-}$

• ${\mathrm{O}}_2^{-}$ is less stable

• ${\mathrm{O}}_2^{+}$ is diamagnetic while ${\mathrm{O}}_2^{-}$ is paramagnetic

• Both ${\mathrm{O}}_2^{-} \mathrm{and} {\mathrm{O}}_2^{+}$ are paramagnetic