Which of the following statements about benzene is true? multiple choice

a. benzene undergoes substitution reactions.

b. benzene has five degrees of unsaturation.

c. benzene is a saturated hydrocarbon.

d. benzene undergoes addition reactions.

option a and d

Explanation:

Option A- Benzene undergoes substitution reaction

Example : benzene reacts with chlorine to form chlorobenzene, in the presence of Iron

(iii) chloride as a catalyst

C6H6 + Cl2 ---> C6H5Cl + HCl

Option D- Benzene also undergoes addition reaction

Example: benzene reacts with hydrogen , in the presence of nickel as a catalyst to form

cyclohexane

C6H6 + 3H2 ---> C6H12

Reasons why Option B isn't the answer

Although benzeme has degree of unsaturation but it's not five degree of unsaturation.

Benzene has 6 carbon atoms and 4 degrees of unsaturation (1 ring and 3 double

bonds).

If you work backwards and double the degrees of unsaturation you have 8 degrees of

unsaturation instead of 5.

Option C - Benzene isn't a saturated hydrocarbon

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.