91Ó°ÊÓ

Chemists have introduced several easy ways to draw chemical structures.In condensed structure carbon-hydrogen and carbon-carbon single bonds are not shown. A carbon bonded to three hydrogens is denoted as ${\mathbf{CH}}_3$and a carbon bonded to two hydrogens is denoted as ${\mathbf{CH}}_2$.

(a)The given structure has eight places where the lines intersect or end. So there are eight carbon atoms in the molecule. The carbon atoms make four bonds. So each carbon atom will have the number of hydrogen atom that are required to make four bonds. The molecular formula of the compound is ${\mathrm{C}}_9{\mathrm{H}}_{13}{\mathrm{NO}}_3$.

Compound (a)

(b)The skeletal structure of Estrone has 18 carbon atoms. The number of bonds that the carbon atom makes can be counted to know the number of hydrogen atoms. The molecular formula of the compound is ${\mathrm{C}}_{18}{\mathrm{H}}_{22}{\mathrm{O}}_2$.

Compound (b)