Which is more stable ,vinyl carbocation or allyl carbocation?

The short answer is Allyl carbonation is more stable than Vinyl carbocation bacuse Allyl carbocation is resonance stabilised where as in case of vinyl carbocation, the positive charge on sp hybridized  carbon, which is highly unstable.

Air contains 20℅ O2 by Volume.How many cc of air will required for oxidation of 100 cc of acetylene?

0.0833 moles of a carbohydrate having empirical formula of CH2O contains one gram hydrogen, find molecular formula

Given EF= CH2O then mass=30

And carbohydrate(CH2O) contains 1gram hydrogen:

From EF it is obvious that 2 grams hydrogen present in 30 grams then 1grams hydrogen present in 15 grams corbohydrate.

Number of moles = Given mass/M.Mass

                              0.0833  =15/M.mass

Then M.mass=180

We Must needed 

Molecular Formula(MF) = n× Empirical Formula (EF)

MF=6(CH2O) = C6H12O6

Where n = Molecular mass/Empirical mass

             n= 180/30=6