Suppose 'A' is a liquid aromatic compound with molecular weight 78 and burns with sooty flame. a. Give the name of the compound 'A' b. write the molecular structure of 'A' C. What is the product when 'A' is treated with ? i. conc. HNO3 with conc. H2SO4 as catalyst ii. Halogen (cl2)in presence of sunlight and mention the use of the product obtained​

Aromatic compounds are compounds that contain carbon-carbon multiple bonds.

The question did not mention that a heteroatom is present in the compound so we can assume that there is none of such. In that case, the compound contains only hydrogen and carbon.

So,

(CH)n = 78

where n is the number of each atom present.

(12 +1)n = 78

n = 78/13

n = 6

The molecular formula of the compound is C6H6

When C6H6 is treated with .conc.HNO3/conc.H2SO4 the compound shown in image 1 is formed. The reaction occurs at the C-C multiple bond.

When C6H6 is reacted with chlorine in the presence of sunlight, hexachlorobenzene (shown in image 2 attached) is formed.

a electronegativity decreases beacuse the size of nucleus is bigger.