Question

The hydrocarbons with general formula \( C_nH_{2n} \) represents:

• A. alkane
• B. alkene
• C. alkyne
• D. cyclic compounds

Hint:

Hydrocarbon formulas:

• Alkanes: \( C_nH_{2n+2} \) (single bonds)
• Alkenes: \( C_nH_{2n} \) (one double bond)
• Alkynes: \( C_nH_{2n-2} \) (one triple bond)
• Cycloalkanes: \( C_nH_{2n} \) (cyclic)

Answer 1

The Correct Option is B

Step 1: Recall general formulas for hydrocarbons.

• Alkanes: \( C_nH_{2n+2} \) (saturated hydrocarbons with single bonds)
• Alkenes: \( C_nH_{2n} \) (unsaturated hydrocarbons with one double bond)
• Alkynes: \( C_nH_{2n-2} \) (unsaturated hydrocarbons with one triple bond)
• Cycloalkanes: \( C_nH_{2n} \) (cyclic saturated hydrocarbons)

Step 2: Analyze the given formula \( C_nH_{2n} \).
The formula \( C_nH_{2n} \) can represent:

• Alkenes (open chain with one double bond)
• Cycloalkanes (cyclic alkanes)

Step 3: Check the options.

• (A) alkane: Incorrect. Alkanes have formula \( C_nH_{2n+2} \).
• (B) alkene: Correct. Alkenes have the general formula \( C_nH_{2n} \).
• (C) alkyne: Incorrect. Alkynes have formula \( C_nH_{2n-2} \).
• (D) cyclic compounds: While cycloalkanes also have formula \( C_nH_{2n} \), the general formula \( C_nH_{2n} \) primarily represents alkenes. Cyclic compounds are a specific category, but the question asks for the general class represented by this formula, which is alkenes.

Step 4: Conclusion.
The general formula \( C_nH_{2n} \) is characteristic of alkenes (unsaturated hydrocarbons with one double bond). Final Answer: (B) alkene