Question

The degree of unsaturation in the given compound is:
1) $C_3{H}_{3}C{l}_3$
2) $C_3{H}_{4}O$
3) $C_4{H}_{5}N$

• A. 2, 1, 3
• B. 1, 2, 3
• C. 3, 2, 1
• D. 2, 3, 1

Answer 1

Answer: (B)

Degree of unsaturation (DoU)$=\frac{2C+2+N-X-H}{2}$

Where $C,N,X$ and $H$ are the numbers of carbons,

Nitrogen, halogens ($F,Cl,Br,I$) and Hydrogens respectively.

$1.C_3{H}_3{U}_3:$ $DoU=\frac{2\times 3+2+0-3-3}{2}=1$

$2.C_3{H}_{4}O:$ $DoU=\frac{2\times 3+2+0-0-4}{2}=2$

$3.C_4{H}_{4}N:$ $DoU=\frac{2\times 4+2+1-0-5}{2}=3$

Correct answer is $B.⟹(1,2,3)$