Chapter 16.2 Test

Question 1

What does the VSEPR theory stand for?

Answer 1

Valence Shell Electron Pair Repulsion Theory

Question 2

What is the VSEPR theory based on?

Answer 2

Based on the fact that an unshared pair of electrons repel more than a single electron.

Question 3

What is a VSEPR model?

Answer 3

A 3D representation of a molecular compound’s structure

Question 4

What are the two factors to look for with respect to the VSEPR structures of molecules?

Answer 4

• The number of atoms bonded to the central atom

- The number of unshared pairs of electrons on the central atom

Question 5

What is a tetrahedral?

Answer 5

A VSEPR structure with 4 atoms bonded to the central atom and no unshared pairs of electrons on the central atom.

Question 6

What is a tetrahedral’s bond angle?

Answer 6

109.5º.

Question 7

What is a pyramidal?

Answer 7

A VSEPR structure with 3 atoms bonded to the central atom and one unshared pair on the central atom.

Question 8

What is the bond angle for a pyramidal?

Answer 8

107º

Question 9

Why do certain VSEPR structures form different bonding angles?

Answer 9

The unshared pairs cause molecules to bond because they repel more and the bond angle goes down.

Question 10

What is a Bent Triatomic?

Answer 10

A VSEPR structure with 2 atoms bonded to the central atoms and one unshared pair of electrons on the central atom.

Question 11

What is the bond angle for a Bent Triatomic?

Answer 11

104.5º

Question 12

What is a Linear Triatomic?

Answer 12

A VSEPR structure with 2 atoms bonded to the central atom and zero unshared pairs on the central atom

Question 13

What is the bond angle for Linear Triatomic?

Answer 13

180º

Question 14

What is a Trigonal Planar?

Answer 14

A VSEPR structure with 3 atoms bonded to the central atom with zero unshared pairs on the central atom

Question 15

What is the bond angle of a Trigonal Planar?

Answer 15

120º

Question 16

What are the exceptions to the Octet Rule?

Answer 16

Trigonal Planar and Trigonal Bipyramidal

Question 17

What is a Trigonal Bipyramidal?

Answer 17

A VSEPR structure with 5 atoms bonded to the central atom with zero unshared pairs on the central atom.

Question 18

What is a linear diatomic?

Answer 18

Two atoms bonded together without a central atom

Question 19

What is a polar molecule’s characteristics?

Answer 19

It must contain polar bonds and does not have molecular symmetry.

Question 20

Why must a polar molecule contain polar bonds?

Answer 20

They create partial charges

Question 21

What is molecular symmetry?

Answer 21

When the same atom is bonded to all possible bonding sites, no unshared pairs of electrons may be on the central atom.

Question 22

What are characteristics of a nonpolar molecule?

Answer 22

• has no charge
• contains nonpolar covalent bonds
• must have molecular symmetry

Question 23

What does symmetry do to partial charges?

Answer 23

It cancels them out

Question 24

What is the relationahip between diatomic molecules and types of molecules?

Answer 24

They have nonpolar covalent bonds and no unshared pairs and no partial or net charges, so they are nonpolar molecules.

Question 25

Can nonpolar molecules contain polar covalent bonds? Why or why not?

Answer 25

Yes, but if they have molecular symmetry, the partial charges are cancelled and it is nonpolar.

Question 26

Practice drawing VSEPR structures, Lewis structures, and assigning partial charges, net charges, write what kinds of bonds are formed, and determine if the molecule is polar or nonpolar

Answer 26

(Draw-use certain molecular compounds for examples.)