What is the suffix used for hydrocarbons with two carbon–carbon double bonds?

What is the suffix used for hydrocarbons with two carbon–carbon double bonds?

• A. En
• B. Yne
• C. Diene
• D. An

Answer: (C)

In hydrocarbon naming, the ending tells you how many carbon–carbon double bonds are present. A single double bond uses the suffix “ene.” When there are two double bonds, the suffix becomes “diene,” indicating two C=C bonds in the molecule. The base name is then adjusted with locants to show where those double bonds occur, such as but-1,3-diene for a four-carbon chain with double bonds at positions 1 and 3. This is why the suffix for hydrocarbons with two C=C bonds is diene.

In hydrocarbon naming, the ending tells you how many carbon–carbon double bonds are present. A single double bond uses the suffix “ene.” When there are two double bonds, the suffix becomes “diene,” indicating two C=C bonds in the molecule. The base name is then adjusted with locants to show where those double bonds occur, such as but-1,3-diene for a four-carbon chain with double bonds at positions 1 and 3. This is why the suffix for hydrocarbons with two C=C bonds is diene.