For each pair of molecules below, which molecule has the greater dipole moment?(a) O_3 or SO_2(b) HBr or HCl

• A. (a) SO_2; (b) HCl
• B. (a) O_3; (b) HBr
• C. (a) SO_2; (b) HBr
• D. (a) O_3; (b) HCl

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what a dipole moment is. The dipole moment (\(\mu\)) is a measure of the separation of positive and negative charges in a molecule and depends on both the magnitude of the charge difference and the distance between the charges. It is a vector quantity, often influenced by molecular geometry and bond polarity.
2. Step 2: For each pair of molecules, analyze their molecular geometry and bond polarity. For example, compare the shapes of \(O_3\) (ozone) and \(SO_2\) (sulfur dioxide), noting that both are bent molecules but differ in bond polarity and electronegativity differences.
3. Step 3: Consider the electronegativity differences between atoms in each molecule. For \(HBr\) and \(HCl\), compare the electronegativities of Br and Cl atoms relative to hydrogen, as this affects the bond dipole moment magnitude.
4. Step 4: Combine the bond dipoles vectorially to determine the overall molecular dipole moment. For bent molecules like \(SO_2\) and \(O_3\), the angle between bonds affects how bond dipoles add up. For diatomic molecules like \(HBr\) and \(HCl\), the dipole moment is directly related to the bond polarity.
5. Step 5: Use the above analyses to decide which molecule in each pair has the greater dipole moment by considering both bond polarity and molecular geometry.