Question

Consider the hydrocarbon below.

H H
\ /
C===C
/ \
H H

What is the name of this hydrocarbon?
propene
pentene
butene
ethene

Answer 1

It is an Alkene because it has a double bond, so it’ll have “ene” at the end. The simplest Alkene has 2 carbons.

2 carbons = “eth”

Look at that! Two carbons! It must be “ethene”

Answer 2

Answer: ethene

Explanation:

The representation of the hydrocarbon is:

H        H
  \       /
  C = C
  /        \
H         H

So, the double C bond means it is an alkene.

The number of  carbon atoms in the molecule is named with the proper prefix:

propa - is used for 3 carbon atoms
penta - is used for 5 carbon atoms
but - is used for 4 carbon atoms
etha - is use for 2 carbon atoms.

Therefore that alkene is name ethene