The incorrect statement regarding ethyne is

<p>To evaluate which statement regarding ethyne is incorrect, it's necessary to review the characteristics of the chemical bonds in ethyne (acetylene, $\mathrm{C_2H_2}$) compared to ethene (ethylene, $\mathrm{C_2H_4}$). </p> <p><strong>Option A:</strong> The statement that the carbon-carbon bonds in ethyne are weaker than that in ethene is <strong>incorrect</strong>. In ethyne, the carbon-carbon triple bond is composed of one sigma ($\sigma$) bond and two pi ($\pi$) bonds. This configuration makes the triple bond in ethyne much stronger and shorter compared to the double bond in ethene, which consists of one $\sigma$ bond and one $\pi$ bond. Thus, the carbon-carbon bond in ethyne is actually stronger than that in ethene. </p> <p><strong>Option B:</strong> The statement that both carbons are sp hybridised in ethyne is <strong>correct</strong>. In ethyne, each carbon atom is bonded to the other carbon atom and a single hydrogen atom, necessitating the sp hybridisation to form a linear molecule with $180^\circ$ angles between the bonds. </p> <p><strong>Option C:</strong> The statement that the $\mathrm{C-C}$ bonds in ethyne are shorter than that in ethene is <strong>correct</strong>. The presence of a triple bond between the carbon atoms in ethyne results in a shorter bond length compared to the double-bonded carbons in ethene. This is because the additional pi bonds in a triple bond pull the carbon atoms closer together. </p> <p><strong>Option D:</strong> The statement that ethyne is linear is <strong>correct</strong>. Due to the sp hybridisation of carbon atoms in ethyne, the molecule adopts a linear geometry with bond angles of $180^\circ$. </p> <p>Therefore, the incorrect statement regarding ethyne is <strong>Option A</strong>: The carbon-carbon bonds in ethyne are weaker than that in ethene.</p>