51.

Consider the following reaction and statements:

$\left[Co\right(N{H}_3{)}_{4}B{r}_2{]}^{+} + B{r}^{-} \stackrel{ }{\to } \left[Co\right(N{H}_3{)}_{3}B{r}_3] + N{H}_3$

(I) Two isomers are produced if the reactant complex ion is a cis-isomer
(II) Two isomers are produced if the reactant complex ion is a trans-isomer
(III) Only one isomer is produced if the reactant complex ion is a trans-isomer
(IV) Only one isomer is produced if the reactant complex ion is a cis – isomer

The correct statements are

• (II) and (IV)

• (I) and (II)

• (I) and (III)

• (III) and (IV)

The trans-alkenes are formed by the reduction of alkynes with

• Sn - HCl

• H₂ – Pd/C, BaSO₄

• NaBH₄

• Na/liq. NH₃

The oxidation states of Cr in [Cr(H₂O)₆]Cl₃,[Cr(C₆H₆)2], and K₂[Cr(CN)₂ (O)₂(O₂)(NH₃)] respectively are :

• +3, +2, and +4

• +3, 0, and +6

• +3, 0, and +4

• +3, +4, and +6

Amongst [Ni(H₂O)₆]²⁺; [Ni(PPh₃)₂Cl₂]; [Ni(CO)₄] and [Ni(CN₄)]^2- the paramagnetic species are

• [NiCl₄]^2-; [Ni(H₂O)₆]²⁺; [Ni(PPh₃)₂Cl₂]

• [Ni(CO)₄]; [Ni(PPh₃)₂Cl₂]; [NiCl₄]^2-

• [Ni(CN₄)]^2- ; [Ni(H₂O)₆]²⁺ ; [NiCl₄]^2-

• [Ni(PPh₃)₂Cl₂] ; [Ni(CO)₄]; [Ni(CN₄)]^2-

Among the following metal carbonyls, the C- O bond order is lowest in

• [Mn(CO)₆]⁺

• [Fe(CO)₅]

• [Cr(CO)₆]

• [V(CO)₆]^-

Point out incorrect stability order

• [Cu(NH₃)₄]²⁺ < [Cu(en)₂]²⁺ < [Cu(trien)]²⁺

• [Fe(H₂O)₆]³⁺ < [Fe(NO₂)₆]^3- < [Fe(NH₃)₆]³⁺

• [Co(H₂O)₆]³⁺ < [Rh(H₂O)₆]³⁺ < [Ir(H₂O₆]³⁺

• [Cr(NH₃)₆]⁺ < [Cr(NH₃)₆]²⁺ < [Cr(NH₃)₆]³⁺

Which one of the following complexes is not expected to exhibit isomerism?

• [Ni(NH₃)₄ (H₂O)₂]²⁺

• [Pt(NH₃)₂Cl₂]

• [Ni(NH₃)₂Cl₂]

• [Ni(em)₃]²⁺

Which of the following carbonyls will have the strongest C-O bond?

• $\mathrm{Mn}(\mathrm{CO}{)}_6^{+}$

• $\mathrm{Cr}(\mathrm{CO}{)}_6$

• $\mathrm{V}(\mathrm{CO}{)}_6^{-}$

• $\mathrm{Fe}(\mathrm{CO}{)}_5$

Which of the following complex compounds will exhibit highest paramagnetic behaviour? (At. no. Ti= 22, Cr= 24, Co= 27, Zn= 30)

• [Ti(NH₃)₆]³⁺

• [Cr((NH₃)₆]³⁺

• [Co(NH₃)₆]³⁺

• [ZN(NH₃)₆]²⁺

Amongst Ni(CO)₄, [Ni(CN)₄]^2- and $\left[{\mathrm{NiCl}}_4^{2-}\right]$

• Ni(CO)₄ and $\left[{\mathrm{NiCl}}_4^{2-}\right]$ are diamagentic but [Ni(CN)₄]^2- is paramagnetic.

• Ni(CO)₄ and [Ni(CN)₄]^2- are diamagnetic but ${\mathrm{NiCl}}_4^{2-}$ is paramagnetic.

• ${\mathrm{NiCl}}_4^{2-}$ and [Ni(CN)₄]^2- are diamagnetic but Ni(CO)₄ is paramagnetic.

• Ni(CO)₄ is diamagnetic but ${\mathrm{NiCl}}_4^{2-}$ and [Ni(CN)₄]^2- is paramagnetic.