Which of the following unsaturated hydrocarbons possesses a non-zero net molecular dipole moment? — Hydrocarbons Chemistry Question

💡 Solution & Explanation

Symmetrical trans-alkenes (like trans-hex-3-ene) and completely symmetrical alkanes (like 2,2-dimethylpropane) have their individual bond dipole moments perfectly cancel out, resulting in a net zero dipole moment. However, trans-pent-2-ene is unsymmetrical ($CH_3$ on one side, $C_2H_5$ on the other), so the dipoles do not fully cancel. cis-isomers (like cis-hex-3-ene) have bond dipoles that add up asymmetrically, creating a net dipole moment.