what is the hdi formula
Up here we had one ring and we had an HDI equal to one. Up here we had one double bond and an HDI equal to one. We could also calculate the HDI using a formula. So we could write that the hydrogen deficiency index is equal to one-half times what's in the parenthesis. Which is two times the number of carbons plus two. That's the whole two n plus two idea. Minus the number of hydrogens. So let's go ahead and do it for this molecular formula with six carbons and six hydrogens.