Which of the following carbonyls will have the strongest $\mathrm{C}-\mathrm{O}$ bond?

Which of the following complex compounds will exhibit highest paramagnetic behaviour?

(At. No. : $\mathrm{Ti}=22, \mathrm{Cr}=24, \mathrm{Co}=27, \mathrm{Zn}=30$ )

Red precipitate is obtained when ethanol solution of dimethylglyoxime is added to ammoniacal Ni(II). Which of the following statements is not true ?

Low spin complex of ${\mathrm{d}}^6$ -cation in an octahedral field will have the following energy: 

(${\mathrm{\Delta }}_{\mathrm{o}}=$ Crystal Field Splitting Energy in an octahedral field, $\mathrm{P}=$ Electron pairing energy)