For each pair of compounds, predict which one has the higher molecular dipole moment, andexplain your reasoning.
(a) ethyl chloride or ethyl iodide
(b) 1-bromopropane or cyclopropane
(c) cis-2,3-dibromobut-2-ene or trans-2,3-dibromobut-2-ene
(d) cis-1,2-dichlorocyclobutane or trans-1,3-dichlorocyclobutane
Answer :
Step 1</p>
(a) ethyl chloride or ethyl iodide
As shown in the figure the iodide has lowest dipole moment of all four kinds of halides present in the periodic table .The C-I bond length is high when compared to C-Cl bond length because the electronegativity of chlorine is high .It makes more significant contribution to the dipole moment .
Due to presence of more electro negativity to the chlorine atom the dipole moment is high to the ethyl chloride molecule .
Step 2</p>
(b) 1-bromopropane or cyclopropane
1-Bromopropane has a polar C-Br bond and has large dipole moment .
Cyclopropane has no electronegative atom and has Zero dipole moment
