Which is the structural formula for pentene?

Which is the structural formula for pentene?

• A. CH2 CH CH2 CH2 CH3
• B. CH3 CH2 CH2 CH2 CH3
• C. CH2 CH CH CH2 CH3
• D. CH3 CH CH2 CH2 CH3

Answer: (A)

Pentene is an alkene with five carbon atoms and one C=C double bond. In a condensed structural form, it is written as CH2=CH-CH2-CH2-CH3, showing the double bond between the first two carbons while the rest of the chain is single-bonded. This arrangement gives the correct hydrogen count for an alkene: the terminal CH2 carries two hydrogens, the internal CH carries one, the following CH2 units carry two each, and the terminal CH3 carries three, totaling C5H10. The option given that appears as CH2 CH CH2 CH2 CH3 corresponds to this pattern when the double bond is shown between the first two carbons, so it reflects the proper five-carbon chain with one double bond. The other representations either depict a fully saturated chain (pentane) or place hydrogens in configurations that do not yield a double bond, which would not be pentene.

Pentene is an alkene with five carbon atoms and one C=C double bond. In a condensed structural form, it is written as CH2=CH-CH2-CH2-CH3, showing the double bond between the first two carbons while the rest of the chain is single-bonded. This arrangement gives the correct hydrogen count for an alkene: the terminal CH2 carries two hydrogens, the internal CH carries one, the following CH2 units carry two each, and the terminal CH3 carries three, totaling C5H10.

The option given that appears as CH2 CH CH2 CH2 CH3 corresponds to this pattern when the double bond is shown between the first two carbons, so it reflects the proper five-carbon chain with one double bond. The other representations either depict a fully saturated chain (pentane) or place hydrogens in configurations that do not yield a double bond, which would not be pentene.