shortcut method of finding hybridisation of compounds

The best method for the purification of carbonyl compound is

Explain, how is the electronegativity of carbon atoms related to the state of hybridisation in an organic compound ?

Which of the following process is/are assciated with change of hybridisation of the underlined compounds?

B_(2)H_(6) on reaction with tri methyl amine from a compound X . Hybridisation of B and N in that compound X is

H_(3)BO_(3) dissolves in liquid HF due to formation of compound X. The hybridisation of central atom in compound X is ,

What is meant by hybridisation ? Compound CH_(2)=C=CH_(2) contains sp or sp^(2) hybridised carbon atoms. Will it be a planar molecule ?