The given question asks about the type of hydrocarbons represented by the general formula \( C_nH_{2n} \). Let's understand the context and options:
Understanding the given formula:
The general formula \( C_nH_{2n} \) indicates the number of carbon (C) and hydrogen (H) atoms in a molecule.
This formula is typically associated with alkenes and cycloalkanes.
Examining the options:
Alkane: This group of hydrocarbons has the general formula \( C_nH_{2n+2} \). Alkanes are saturated hydrocarbons. So, this is not the correct option.
Alkene: Represented by the general formula \( C_nH_{2n} \), alkenes are unsaturated hydrocarbons containing at least one carbon-carbon double bond. Hence, this is a correct option.
Alkyne: Alkynes have the general formula \( C_nH_{2n-2} \) and contain a carbon-carbon triple bond. Thus, this is not the correct option.
Cyclic Compounds: Cycloalkanes can also have the general formula \( C_nH_{2n} \), but they are saturated hydrocarbons. However, since the most common association with \( C_nH_{2n} \) in the context of alkenes, this is an additional consideration but not usually the primary one when alkenes are specifically in the options.
Conclusion: The correct answer is alkene, as it perfectly fits the general formula \( C_nH_{2n} \) for unsaturated hydrocarbons with a double bond.