The degree of unsaturation, or index of hydrogen deficiency, is the number of pi bonds plus rings in a molecule. Specify the degree of unsaturation (index of hydrogen deficiency) of the following formulas: (a) C5H6
(b) C10H6Cl2
(c) C4H3NO

Explanation:

The degree of unsaturation is given as;

Degree of unsaturation = (2C + 2 + N - H - X) / 2

(a) C5H6

Using the formular above;

Degree of unsaturation = [ 2(5) + 2 - 6] / 2

Degree of unsaturation = [ 12 - 6 ] / 2 = 3

(b) C10H6Cl2

Using the formular above;

Degree of unsaturation = [ 2(10) + 2 - 6 -2 ] / 2

Degree of unsaturation = [ 22 - 8 ] / 2 = 7

(c) C4H3NO

Using the formular above;

Degree of unsaturation = [ 2(4) + 2 - 3 -1 ] / 2

Degree of unsaturation = [ 10 - 4 ] / 2 = 3

Note: Oxygen is ignored because its presence has no effect on the degree of unsaturation.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !