Question

Which formula represents an unsaturated hydrocarbon? (1) C5H12 (3) C7H16 (2) C6H14 (4) C8H14

Answer 1

Answer:

Answer is C₈H₁₄

Explanation:

The general molecular formula of alkanes (saturated hydrocarbons) is:

CₙH₂ₙ₊₂

Where n = number of carbon atoms.

The general molecular formula of alkenes (unsaturated hydrocarbons) is:

CₙH₂ₙ

The general molecular formula of alkynes (unsaturated hydrocarbons) is:

CₙH₂ₙ₋₂

Now let us check the formula of given compounds

a)C₅H₁₂

n = 5

2n=10

2n+2=12

so this is an alkane, saturated hydrocarbon.

b)C₇H₁₆

n = 7

2n=14

2n+2=14

so this is an alkane, saturated hydrocarbon.

c)C₆H₁₄

n = 6

2n=12

2n+2=14

so this is an alkane, saturated hydrocarbon.

d) C₈H₁₆

n = 8

2n=16

2n+2=18

2n-2=14

so this is an alkyne, unsaturated hydrocarbon.

Answer 2

(4) C8H14 is your answer. A saturated hydrocarbon means that they have no double or triple bonds. C8H14 is an alkyne, which is an unsaturated hydrocarbon.