Answer:
One ring is present.
Explanation:
The degree of unsaturation or double bond equivalents(DBE) can be determined by using a formula. This formula gives us the number of rings and / pi bonds.
As mentioned in the problem the number of pi bond is one so if we calculate the DBE this will give us the number of rings by subtracting one from DBE.
[tex]DBE=C+1-\frac{H}{2}-\frac{X}{2}+\frac{N}{2}[/tex]
Where
C = number of carbon atoms
X = number of halogens
N = number of nitrogen
H = number of hydrogen
[tex]DBE=15+1-(\frac{28}{2})-(0)+(0)[/tex]
[tex]DBE=16-14=2[/tex]
Thus the number of rings will be:
[tex]Rings=2-1=1[/tex]
