Dipole moment and molecular polarity
Chemical Bonding (Basics) · Chemistry
Study notes
CO₂ has polar C=O bonds but is nonpolar. H₂O has polar O–H bonds and IS polar. Why? Step 1: Both have polar bonds (O more electronegative than C/H). Step 2: CO₂ is linear: two equal dipoles point oppositely → cancel → μ = 0. Step 3: H₂O is bent: dipoles point partly same way → add → μ = 1.85 D. Step 4: Rule: polar bonds + asymmetric shape = polar molecule. CCl₄ (tetrahedral) also cancels → nonpolar despite polar C–Cl bonds.