Question

The distance between two adjacent carbon atoms is largest in

• A. benzene
• B. ethene
• C. butane
• D. ethyne

Answer 1

The Correct Option is C

To determine where the distance between two adjacent carbon atoms is largest, we need to analyze the structures of the given chemical compounds: benzene, ethene, butane, and ethyne.

1. Benzene: In benzene, the carbon atoms are arranged in a planar hexagonal ring with alternating single and double bonds. The bond length between the carbon atoms in benzene is approximately 1.39 Å due to resonance, which makes all the C-C bonds equivalent.
2. Ethene: Ethene (\(C_2H_4\)) contains a carbon-carbon double bond. The length of a typical C=C double bond is around 1.34 Å, which is shorter than a single C-C bond.
3. Butane: Butane (\(C_4H_{10}\)) is an alkane, which consists of single bonds between carbon atoms. A typical C-C single bond length is approximately 1.54 Å. This is longer than a C=C double bond or a C≡C triple bond.
4. Ethyne: Ethyne (\(C_2H_2\)) contains a carbon-carbon triple bond. The length of a C≡C triple bond is shorter, around 1.20 Å.

Comparing these values, the C-C single bond length in alkanes (butane in this case) is the longest at 1.54 Å. Therefore, the distance between two adjacent carbon atoms is largest in butane.

Conclusion: The correct answer is butane, as it has the longest C-C bond length among the given options.