Magnesium heated with carbon in an electric furnance gives a compound (A). 'A' on heating changes to 'B'. Hydrolysis of 'B' gives a hydrocarbon 'C'. The number of sp carbons in the compound 'C' is ____

No. of sp^2 hybridised carbons in compound (B)

Sodium carbonate on heating gives:

A water soluble compound 'A' having molecular formula C_3H_6O gives yellow crystalline solid on heating with iodine and sodium carbonate. The compound 'A' is

In the presence of dry ether, formaldehyde (A) undergoes nucleophilic addition with Grignard reagent (obtained from methyl iodine and metallic magnesium ) to give compound 'B' . The compound 'B' on heating with diazomethane in the presence of fluorboric acid gives compounds 'C'. Identify compound 'B' and 'C' .