Shapes and Polarity Tutorial

What theory explains the geometric structure (3D shape) of a molecule based on electron pair repulsion?

• Quantum Mechanical Model

• Valence Bond Theory

• VSEPR Theory

• Molecular Orbital Theory

What does the acronym VSEPR stand for?

How many bonding domains does a molecule with a trigonal planar shape have?

• 3

• 4

• 1

• 2

Does a molecule with Trigonal Planar shape have any lone pairs on the central atom?

• Yes

• No

How many bonding domains does CH₄ have?

• 1

• 2

• 3

• 4

What is the shape of CH₄?

• Trigonal pyramidal

• Trigonal planar

• Tetrahedral

• Linear

Answer explanation

You have to draw the Lewis Structure first.

Then determine how many bonding domains the molecule has.

CH₄ has 4 bonding domains.

(In this class) everything with 4 bonding domains is tetrahedral.

How many bonding domains does arsenic trihydride (AsH₃) have?

• 1

• 2

• 3

• 4

Does arsenic trihydride (AsH₃) have any lone pairs on the central atom?

• Yes

• No

What is the shape of arsenic trihydride (AsH₃)?

• Trigonal pyramidal

• Trigonal planar

• Tetrahedral

• Linear

What determines if a molecule is polar?

• If it contains at least one polar bond

• If the bond dipoles do not cancel out

• If the molecule's bonds are symmetrically arranged

• If the bond dipoles cancel out