Hydroformylation of olefins yields

What do you mean by hydroformylation of olefins ?

Which catalyst is used in the hydroformylation of olefins? Give equation.

Acylation of benzene to produce aliphatic aromatic ketones is known as Benzoin condensaion Hydroformylation Clemmensen reduction Friedel-Crafts' reaction

The catalyst used for the polymerisation of olefins is

The catalyst used for the polymerisation of olefins is