Molecular Compounds and Nomenclature

Question 1

Binary Covalent Compounds (Type III)

Answer 1

Formed between two nonmetals

Different from ionic because ionic has a metal and nonmetal!

Question 2

What does the Lewis Structure show?

Answer 2

How valence electrons are arranged among atoms in a molecule

Question 3

Octet Rule

Answer 3

When making bonds, the elements want to have a full otect (or 8 electrons)

Question 4

How are bonding pairs represented in Lewis structures?

Answer 4

With a dash

one dash = 2 electrons

Question 5

Duet Rule

Answer 5

Only applies to hydrogren. Hydrogen wants to have two electrons to fill its orbital

Question 6

Single covalent bond

Answer 6

Covalent bond in which two atoms share one pair of electrons

Double covalent bonds and triple covalent bonds follow the same idea!

Question 7

Electronegativity

Answer 7

Ability of an atom in a molecule to attract shared electrons to itself

Question 8

On the periodic table, what pattern does electronegativity follow?

Answer 8

Increases across a period and decreases down a group

Literally the same pattern as ionization energy (metals lose eletcrons!)

Question 9

Steps for writing lewis structures

Answer 9

1. Sum valence elctrons for all atoms
2. Determine central atom (usually one with lowest electronegativity)
3. Use a dash to form a bond between each pair of bound atoms
4. Arrange remaining electrons to satisfy the octet (or duet rule)

Question 10

Lewis structure exceptions

Answer 10

1. Boron does not make octet
2. Be is a metal but can form a covalent bond with a non-metal
3. Non-metals in period 3 and below (S, P, etc.)
   have expanded valence shell and exceed the
   octet rule.

Question 11

Do halogens make double bonds?

Answer 11

NO

Question 12

After drawing a Lewis structure for an ion, what must we draw around it?

Answer 12

A set of brackets with the charge of the ion

Question 13

Delocalized

Answer 13

Not stationary, elctrons can move around the whole molecule

Question 13

Delocalized

Answer 13

Not stationary, elctrons can move around the whole molecule

Question 14

Formal Charge

Answer 14

(number of valence eletcrons on free atom) - (number of valence elctrons assigned to the atom in the molecule)

Question 15

What is the typical formal charge for carbon?

Answer 15

0

Question 16

What does VSEPR stand for?

Answer 16

Valence shell electron pair repulsion

Question 17

What is the goal of the VSEPR model?

Answer 17

To minimize repulsion between the electrons

Question 18

What is the purpose of elctron geometry?

Answer 18

To determine bond angles

Question 19

Electron group number

Answer 19

Each single, double, or triple bond counts as one electron group. Each lone pair counts as one electron group.

Question 20

2 electron group bond angle

Answer 20

180 degrees (linear)

Question 21

3 electron group bond angle

Answer 21

120 degrees (trigonal planar)

Question 22

4 electron group bond angle

Answer 22

109.5 degrees (tetrahedral)

Question 23

5 electron group bond angle

Answer 23

90 and 120 degrees (trigonal-bipyramidal)

Question 24

6 electron group bond angle

Answer 24

90 degrees (octahedral)

Question 25

Difference between electron geometry and actual (molecular) geometry

Answer 25

Electron geometry takes into account both the bond electron pairs and lone electron pairs. Actual geometry only takes into account the bond electron pairs

Question 26

In trigonal bipyramidal electron geometry, which plane do the love pairs occupy?

Answer 26

equatorial plane

Question 27

Where do we get the shape of molecules from?

Answer 27

Molecular or actual geometry

Question 28

Where do bond angles come from?

Answer 28

Electron geometry