What is the Index of Hydrogen Deficiency?

Question

What is the index of hydrogen deficiency of C6H12ClN ?

and how do you work it out?

Answer 1

http://en.wikipedia.org/wiki/Degree_of_u...

"The formula for degree of unsaturation is

[(2C +2) - (H's & X's) + N ] / 2



where C is the numbers of carbon atoms, H is the numbers of hydrogen atoms, X is the numbers of halide atoms, and N is the numbers of nitrogen atoms. Do not count group VI elements such as oxygen and sulfur atoms (but count H groups attached to oxygen atoms, such as hydroxyl groups). Halogen atoms (F, Cl, Br, I) count as H atoms for degree of unsaturation calculations."

so a C6 molecule would max out w/ Hydrogens @ 2n+2 = 14 H's,

it has 12H's & 1 Cl  for 13, but the Nitrogen replacing the 14th Hydrogen has H-needs of its own (need for 2 additional H's),  thus increasing the total need to 14.  2 H's are still missing, there is 1 unsaturation, (either a ring , or a double bond)

the formula method:

[(2C +2) - (H's & X's) + N ] / 2

[(2(6) +2) - (12 & 1) + 1 ] / 2

[(14) - (13) + 1 ] / 2

(15 -13) / 2

2/2

your answer 1s:  "1"