The pair in which both species have same magnetic moment (spin only value) is

• [Cr(H₂O)₆]²⁺,[CoCl₄]²⁺

• [Cr(H₂O)₆]²⁺,[Fe(H₂O)₆]²⁺

• [Mn(H₂O)₆]²⁺, [Cr(H₂O)₆]²⁺

• [CoCl₄]^2-, [Fe(H₂O)₆]²⁺

Which gives nucleophilic addition most easily :

• CH₃CHO

• CH₃CH₂CHO

• (CH₃)₂CHCHO

• HCHO

The colour imparted by Co(II) compounds to glass is

• green

• deep-blue

• yellow

• red

The number of possible isomers of an octahedral complex[Co(C₂O₄)₂(NH₃)₂]^- .

• 1

• 2

• 3

• 4

The ligands in anti-cancer drug cisplatin are

• NH_3, Cl

• NH₃, H₂O

• Cl, H₂O

• NO, Cl

The magnetic moment of K₃[Fe(CN)₆]  is found to be 1.7 BM .How many unpaired electron (s) is/are present per molecule ?

• 1

• 2

• 3

• 4

In [Ag(CN)₂]^-, the number of $\mathrm{\pi }$ bonds is

• 2

• 3

• 4

• 6

An aqueous solution of CoCl₂ on addition of excess of concentrated HCl turns blue due to formation of

• [Co(H₂O)₄Cl₂]

• [Co(H₂O)₂Cl₄]^2-

• [CoCl₄]^2-

• [Co(H₂O)₂Cl₂]

279.

In which of the following pairs both the complexes show optical isomerism?

• cis-[Cr(C₂O₄)₂Cl₂]^3-, cis-[Co(NH₃)₄Cl₂]

• [Co(en)₃]Cl₃, cis-[Co(en)₂Cl₂]Cl

• [PtCl(dien)]Cl, [NiCl₂Br₂]^2-

• [Co(NO₃)₃(NH₃)₃], cis-[Pt(en)₂Cl₂]

The correct order for the wavelength of absorption in the visible region is

• [Ni(NO₂)₆]^4- < [Ni(NH₃)₆]²⁺ < [Ni(H₂O)₆]²⁺

• [Ni(NO₂)₆]^4- < [Ni(H₂O)₆]²⁺ < [Ni(NH₃)₆]²⁺

• [Ni(H₂O)₆]²⁺ < [Ni(NH₃)₆]²⁺ < [Ni(NO₂)₆]^4-

• [Ni(NH₃)₆]²⁺ < [Ni(H₂O)₆]²⁺ < [Ni(NO₂)₆]^4-