b) How is a metal-carbon `pi` bond formed in metal carbonyls? 

The metal-carbon bond in metal carbonyls prossesses :

What is metallic bond?

Give Reason: a. Prior to reduction of the metal, sulphides and metal carbonates must be converted into metal oxides. b. for extracting some metals, displacement reactions are used instead of carbon to obtain metals from their oxides.

Explain synergic effect in the formation of metal carbonyls.

A metal is slowly eaten away in the presence of air and water. To avoid this, the metal is mixed with carbon, choromium, and nickel. a. Identify the metal. b. What is the substance formed on mixed with carbon? c. State another method that can be used to protect the metal.

Wittig reaction : The reaction of a phosphorus ylide with an aldehyde (or) ketone introduces a carbon-carbon double bond is place of the carbonyl bond. Driving froce of the reaction is high bond energy of (P = O). (DeltaH=-ve) . , Major product (A) is :