Molecular Geometry & Polarity — Drills · Grade 11 Science
Chapter: Bonding, Formulas & Molecular StructureWhat these drills covers
By the end of Molecular Geometry & Polarity you should be able to:
- I can use VSEPR theory to predict the shape of a simple molecule from its bonding groups and lone pairs.
- I can decide whether a bond and a whole molecule are polar or nonpolar, and name the main intermolecular forces.
6 questions, multiple choice, numeric and written answer, each with a worked explanation.
Vocabulary used: VSEPR theory, molecular geometry, electronegativity, polar bond, nonpolar bond, dipole, intermolecular force, hydrogen bond.
Problem 1
- mass
- temperature
- color
- three-dimensional shape
Answer and explanation
three-dimensional shape
VSEPR predicts molecular shape from how electron groups repel and spread out.
Problem 2
- linear
- trigonal pyramidal
- bent
- tetrahedral
Answer and explanation
linear
Two groups push to opposite sides, giving a linear (180°) shape.
Problem 3
Answer and explanation
109.5 °
Four electron groups spread to the corners of a tetrahedron, giving angles of about 109.5°.
Problem 4
- dipole–dipole forces
- hydrogen bonds
- there are no forces between molecules
- London dispersion forces
Answer and explanation
hydrogen bonds
Hydrogen bonds are the strongest intermolecular force, followed by dipole–dipole, then London dispersion.
Problem 5
Answer and explanation
If the molecule's shape is symmetric, the individual bond dipoles point in directions that cancel each other, leaving no net dipole. For example, CO₂ has two polar bonds but is linear and symmetric, so its dipoles cancel and the molecule is nonpolar.
Problem 6
- CO₂ (linear)
- CH₄ (tetrahedral)
- H₂O (bent)
- BF₃ (trigonal planar)
Answer and explanation
H₂O (bent)
Water's bent shape means its bond dipoles don't cancel, so it has a net dipole and is polar. The other three are symmetric, so their dipoles cancel.