Question

For the formula C4H9Cl , calculate the index of hydrogen deficiency (IHD) and select all the types of unsaturation that might be present in the molecule based on the IHD.

Answer 1

IHD = 0; no unsaturation in the formula

Step-by-step explanation:

The IHD is also known as the degree of unsaturation formula. This formula is commonly used to get an idea of how many unsaturations a molecule has, and in this way, we can get an approach of the type of compound we are treating. For example, if this number is 1, it means that the compound has at least one unsaturation and it could be a double bond or just cyclical compound.

The IHD is calculated using the following expression:

IHD = (a + 1) - (b + x - c)/2 (1)

Where:

a: number of carbon

b: number of hydrogens

c: humber of nitrogens

x: number of halogens.

Now, we have the formula C₄H₉Cl, let's identify a, b, c and x:

a: 4 carbons; b = 9 hydrogens; C = none; X: 1 chlorine

Replacing in (1) we have:

IHD = (4+1) - (9+1)/2

IHD = 5 - (10/2)

IHD = 0

So this number is 0, which means that the molecule does not have any kind of unsaturation (Non double bond, multi bond or cyclical).

Hope this helps