The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecule is:

The major organic compound formed by the reaction of 1, 1, 1– trichloroethane with silver powder is:

Sodium phenoxide when heated with $$C{O_2}$$ under pressure at $${125^ \circ }C$$ yields a product which on acetylation products $$C.$$



The major product $$C$$ would be

Which one of the following bases is not present in DNA?