Question

Which formula represents an unsaturated

organic compound?
(1) CH4 (3) C3H8
(2) C2H4 (4) C4H10

Answer 1

The only saturated hydrocarbons are Alkanes:
`C_(n) H_(2n+2)`

From that we can see that:
CH4, C3H8 and C4H10 are saturated.

Therefore:
C2H4 is unsaturated. Answer is (2).

Answer 2

Answer: (2)
`C_2H_4`

Explanation: Unsaturated organic compounds are those compounds which contains carbon-carbon double or triple bond.

Saturated organic compounds are those compounds which contains carbon-carbon single bond.

`CH_4`,
`C_3H_8` and
`C_4H_10` are all alkanes having general formula
`C_nH_(2n+2)` containing single bonds.

`C_2H_4` is an alkene having general formula
`C_nH_(2n)` containing double bonds.