Which of the following metal carbonyls is synthesized by the drect interaction of finely divided metal with CO ?

Which one of the following metal carhonyls is prepared by the direct interaction of finely divided metal with CO ?

Which of the following is not a metal carbonyl?

Which of the following metal carbonyl has structure in the diagram?

Which of the following metal carbonyl has structure in the diagram?

In metal carbonyls, there is -

In metal carbonyls, there is -

Which of the following metal carbonyls has the longest C-O bond length ?