Answer
(a) Adrenaline
Molecular Formula - $C_{9}$$H_{13}$$N$$O_{3}$
Number of Hydrogen Atoms bonded to each Carbon = 9
(b)Estrone
Molecular Formula - $C_{18}$$H_{22}$$O_{2}$
Number of Hydrogen Atoms bonded to each Carbon = 21
Work Step by Step
1. A Carbon bonded to only one atom other than Hydrogen has 3 Hydrogen atoms attached to it. (called a 1$^{\circ}$Carbon or primary Carbon)
2. A Carbon bonded to two atoms other than Hydrogen has 2 Hydrogen atoms attached to it. (called a 2$^{\circ}$Carbon or secondary Carbon)
3. A Carbon bonded to either three atoms other than Hydrogen has 1 Hydrogen attached to it.(called a 3$^{\circ}$Carbon or tertiary Carbon)
4. A Carbon bonded to four atoms other than Hydrogen has no Hydrogen attached to it. (called a 4$^{\circ}$Carbon or quarternary Carbon)
5. A Carbon atom having a double bond with another atom has 2 Hydrogen atoms attached to it.
6. A Carbon atom having a triple bond with another atom has only 1 Hydrogen atom attached to it.
7. A single line with no atom at the end represents a Carbon atom with 3 Hydrogens attached to it
Now, on close inspection of the structures of Adrenaline and Estrone, we find that:
(a) for Adrenaline
Number of 1$^{\circ}$C or primary carbon = 1
so, total number of Hydrogen atoms on this carbon = 3
Number of 2$^{\circ}$C or secondary carbon = 1
so, total number of Hydrogen atoms on this carbon = 2
Number of 3$^{\circ}$C or tertiary carbon = 4
so, total number of Hydrogen atoms on these carbon atoms = 4
Number of 4$^{\circ}$C or quarternary carbon = 3
so, total number of Hydrogen atoms on these carbon atoms = 0
Hence, total number of Hydrogen atoms = 9
(b) for Estrone
Number of 1$^{\circ}$C or primary carbon = 1
so, total number of Hydrogen atoms on this carbon = 3
Number of 2$^{\circ}$C or secondary carbon = 6
so, total number of Hydrogen atoms on this carbon = 12
Number of 3$^{\circ}$C or tertiary carbon = 6
so, total number of Hydrogen atoms on these carbon atoms = 6
Number of 4$^{\circ}$C or quarternary carbon = 4
so, total number of Hydrogen atoms on these carbon atoms = 0
Hence, total number of Hydrogen atoms = 21
