Double bond equivalent:-
Double bond equivalent is a method of calculation to calculate the double bond or ring present in the given chemical formula . When you draw the structure of chemical formula then need to the value of double bond equivalent value. it is also known as degree of unsaturation. Formula of double bond equivalent is given below,
DBE = (2*C + 2 - H - X + N ) /2
Where,
C = No of carbon atoms
H = No of hydrogen atoms
X = No of halogen atoms ( F, Cl, Br, I, At )
N = No of nitrogen atoms
Example:-
Let the chemical formula is C7H8O. then find the value of double bond equivalent ?
Solution:-
Given,
No of carbon = 7
No of hydrogen = 8
No of halogen atoms = 0
No of nitrogen atoms = 0
DBE = (2*7 + 2 - 8 - 0 + 0)/2
= 8/2
= 4
Structure defines according to DBE value:-
A comman use of DBE value is that, how to create a molecular structure when molecular weight is given. Condition is given below,
1. If DBE value is one :-
It is denoted that a ring or a double bond present in the molecular structure.
Example:- C6H12 , C3H6, C3H6O etc.
2. If DBE value is two:-
It denoted that a ring and a double bond or two double bond present in the molecular structure.
