Identify all of the compounds that contain polar bonds but which are non-polar overall: Group of answer choices a: SO2 b: SO3 c:SCl4 d: HCN e: CH4 f: NF3 g: PBr5 h: BF3 i: H2S
The Correct Answer and Explanation is:
To identify the compounds that contain polar bonds but are non-polar overall, we need to consider both bond polarity and molecular geometry.
A polar bond forms between atoms with different electronegativities. However, a molecule can still be non-polar overall if its molecular geometry causes the bond dipoles to cancel out.
Let’s evaluate each compound:
a: SO₂ (Sulfur dioxide)
- Contains polar bonds (S–O)
- Bent shape
- Dipoles do not cancel
➡️ Polar overall
b: SO₃ (Sulfur trioxide)
- Contains polar bonds (S–O)
- Trigonal planar shape
- Dipoles cancel out
➡️ Non-polar overall
c: SCl₄ (Sulfur tetrachloride)
- Contains polar bonds (S–Cl)
- Seesaw shape due to one lone pair
- Dipoles do not cancel
➡️ Polar overall
d: HCN (Hydrogen cyanide)
- Contains polar bonds (H–C, C≡N)
- Linear shape
- Dipoles do not cancel
➡️ Polar overall
e: CH₄ (Methane)
- Contains weakly polar bonds (C–H)
- Tetrahedral symmetry
- Dipoles cancel out
➡️ Non-polar overall
f: NF₃ (Nitrogen trifluoride)
- Contains polar bonds (N–F)
- Trigonal pyramidal shape
- Dipoles do not fully cancel
➡️ Polar overall
g: PBr₅ (Phosphorus pentabromide)
- Contains polar bonds (P–Br)
- Trigonal bipyramidal shape
- Dipoles cancel out due to symmetry
➡️ Non-polar overall
h: BF₃ (Boron trifluoride)
- Contains polar bonds (B–F)
- Trigonal planar shape
- Dipoles cancel out
➡️ Non-polar overall
i: H₂S (Hydrogen sulfide)
- Contains polar bonds (H–S)
- Bent shape
- Dipoles do not cancel
➡️ Polar overall
✅ Correct Answer:
b: SO₃, e: CH₄, g: PBr₅, h: BF₃
These compounds contain polar bonds but are non-polar overall due to their symmetrical geometries that cancel out the dipole moments.
