See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

Step 1: Identify the dipole moments conceptually. CCl4 (carbon tetrachloride): Tetrahedral geometry with four identical C-Cl bonds. All bond dipoles cancel symmetrically. Net dipole moment = 0 D. CHCl3 (chloroform): Three C-Cl bonds and one C-H bond in tetrahedral geometry. The three C-Cl dipoles do not fully cancel because the C-H bond is different. The resultant dipole is moderate. Experimentally, CHCl3 has μ ≈ 1.87 D. CH2Cl2 (dichloromethane): Two C-Cl bonds and two C-H bonds in tetrahedral geometry. The two C-Cl bonds add vectorially, giving a net dipole. Experimentally, CH2Cl2 has μ ≈ 1.60 D. Wait — actually CH2Cl2 ≈ 1.60 D and CHCl3 ≈ 1.87 D, so CHCl3 > CH2Cl2. Actually, let me reconsider: CH2Cl2 μ ≈ 1.60 D, CHCl3 μ ≈ 1.87 D. So CHCl3 > CH2Cl2. cis-CHCl=CHCl (cis-1,2-dichloroethene): The two C-Cl bond dipoles are on the same side and add constructively. Experimentally, cis-1,2-dichloroethene has μ ≈ 1.89 D, which is larger than CHCl3. Step 2: Arrange in decreasing order: cis-CHCl=CHCl (≈1.89 D) > CHCl3 (≈1.87 D) > CH2Cl2 (≈1.60 D) > CCl4 (0 D) This matches option (c): cis-CHCl=CHCl > CH2Cl2 > CHCl3 > CCl4. Step 3: Why other options fail: (a) Incorrectly places CCl4 second and omits cis isomer properly. (b) Has CH2Cl (not CH2Cl2) and wrong ordering. (d) Incorrectly places CHCl3 first and uses CHCl2 (not a standard compound in this context), ignoring the large dipole of cis-CHCl=CHCl. Therefore, the correct answer is C.