Ch.2 Bonding and Intermolecular forces

Question 1

What is a molecule?

Answer 1

any structure composed of multiple atoms

Question 2

What is a compound?

Answer 2

a molecule that has atoms of more than one element connected together

Question 3

When discussing nomenclature, how do you name binary compounds?

Answer 3

Ionic compounds - list cation first, then Anion second
Molecular compound - Arrange in order of electronegativity. (exception list carbon first, hydrogen after nitrogen)
Prefixes and suffixes are used in molecular compounds

Question 4

What is an Ionic compound?

Answer 4

A metal and nonmetal molecule

Question 5

What is a molecular compound?

Answer 5

It contains 2 nonmetals

Question 6

In Ionic compounds why is it important that metal is identified with roman numerals?

Answer 6

Because it shows the oxidation state.

This allows us to determine how many electrons are being shared with another atom.

Question 7

Forces that hold atoms together within a molecule are called?

Answer 7

Intramolecular forces

Question 8

Forces that determine how molecules interact with each other are?

Answer 8

Intermolecular forces

Question 9

What are the various types of Intramolecular forces?

Answer 9

Covalent, Ionic, and Metallic bonds

Question 10

What is a covalent bond?

Answer 10

a bond formed between 2 nonmetals, by sharing valence electrons.
(they share electrons because their electronegativity lvl is similar)

Question 11

What is a nonpolar covalent bond?

Answer 11

An element with the same (or similar) electronegativity are bonded together.

Question 12

What is a polar covalent bond?

Answer 12

Atoms with a moderate difference in electronegativity are bonded together.

Question 13

Covalent bonds have 2 different electronegativity values, what are they?

Answer 13

< .5 = nonpolar
.5 - 1.7 = polar
(greater than 1.7 = Ioninc bonds)

Question 14

Since polar molecules unequally share electrons, a stable dipole forms. What is a dipole?

Answer 14

A dipole is a depiction of the vector of shared electrons.

A line with a plus is drawn.

Question 15

What is an Ionic bond?

Answer 15

A complete transfer of one or more valence electrons (electronegativity must be >1.7).
Ionic bonding occurs between metal and nonmetal, and is stronger than covalent bonding.

Question 16

Which is stronger covalent or Ionic?

Answer 16

Ionic bonding

Question 17

Which type of force is stronger, intramolecular or intermolecular?

Answer 17

Intramolecular

Question 18

What are the types of intermolecular bonding

Answer 18

London dispersion
Dipole-dipole
Hydrogen
Ion-dipole
Ionic interactions
(in order from least to greatest)

Question 19

What is a London dispersion force?

Answer 19

Occur when temporary dipoles arise by chance

larger structure will have a greater force

Question 20

What is a Dipole-dipole interaction?

Answer 20

Occur between polar molecules.
It is a attractive force that occurs between the positive dipole of one polar molecule and the negative dipole of another.

Question 21

Explain hydrogen bonding

Answer 21

It is not true bonding
When hydrogen is attracted to lone pairs on nitrogen, oxygen, or fluorine. These molecules are highly electronegative and form strong bonds with hydrogen

Question 22

What are Ion-dipole forces?

Answer 22

These atrractions occur between an ion (charged molecule/atom) and a molecule with a dipole.

Question 23

The stronger intermolecular forces a compound has, the _________ it’s melting/ boiling point.

Answer 23

Higher

Question 24

When counting valence electrons a bond counts as how many electrons?

Answer 24

2

Question 25

Bond formation is considered a energy-________ reaction?

Answer 25

releasing (exothermic)

Question 26

Which molecules have exceptions to the octet rule, in which they can contain less?

Answer 26

hydrogen, Helium, and lithium = 2 electrons Beryllium = 4 electrons Boron = 6 electrons

Question 27

Which molecules have exceptions to the octet rule, in which they can contain more?

Answer 27

Atoms in the 3rd period and below. | Odd-electron molecules

Question 28

Typically metals (group 1 & 2) form _____ bonds with nonmetals (especially halogens). The electronegativity for this bind is?

Answer 28

Ionic bonds, electronegativity >1.7

Question 29

_________ compounds have a crystal lattice structure and high melting points due to the intramolecular forces.

Answer 29

Ionic

Question 30

__________ dissociates in an aqueous solution, which causes the solution the ability to conduct electricity.

Answer 30

Ionic compounds (electrolytes)

Question 31

Compared to ionic bonds, the elctronegativity difference for covalent bonds are

Answer 31

Smaller (.5)

Question 32

______ results from the complete donation or acceptance of electrons from an atom. While ______ share electrons.

Answer 32

Ionic bonds | Covalent bonds

Question 33

What are the most common polar and nonpolar covalent bonds?

Answer 33

``` C-H = nonpolar C-N = slightly polar N-H = moderatly polar O-H & F-H = Highly polar C- O = meaningful polar (less than H-O) ```

Question 34

What is a coordinate covalent bond?

Answer 34

a bond that forms when a set of lone pair electrons is shared with another atom without electrons to share.

Question 35

What is bond order?

Answer 35

number of bonds between two atoms

Question 36

Distinguish between sigma and pi bonds

Answer 36

Sigma bonds are the first single bonds to form (it represents the electrons shared between two molecules). Pi bonds are each additional bonds

Question 37

Describe bond length

Answer 37

Distance between bonded atoms, or the distance between the nuclei of the atoms that are in the bond. Bond length is inversely related to bond order. single bond = furthest

Question 38

Describe bond energy

Answer 38

the energy required to break covalent bonds. | The higher the bond energy (triple) the harder to break. Bond energy is therefore directly related to bond order.

Question 39

What is formal charge?

Answer 39

The disparity between the number of valance electrons an atom should have (periodic table) and the number it actually has.

Question 40

What is the equation for formal charge?

Answer 40

FC = Valence elctrons - 1/2bonding electrons - Lone pairs of electrons

Question 41

Discuss hybridizations of orbitals

Answer 41

``` 1s 1p = 2 sp orbitals 1s 2p = 3 sp2 orbitals 1s 3p = 4 sp3 orbitals Determine electron density around atom (bonds or lone pairs). If there are two region = sp three regions = sp2 four regions = sp3 ```

Question 42

What is the VESPR theory?

Answer 42

uses # of bonds and lone pairs to predict shape

Question 43

What are the various angles of VESPR?

Answer 43

``` Bent (water) - 104.5 Trigonal pyramidal - 107 Tetrahedral - 109.5 Trigonal planar - 120 Linear - 180 ```

Question 44

There are a few elements that do not follow the octet rule, what are they?

Answer 44

Hydrogen - only 1 Helium and lithium - maximum of two Berilium - maximum of 4 Boron - max of 6

Question 45

When drawing a Lewis dot structure, which atom should be center?

Answer 45

The one with the lowest electronegativity

Question 46

After forming single bonds and calculating the remaining valence electrons for a Lewis dot structure, where should the remaining electrons go?

Answer 46

To the peripheral atoms

Question 47

Resonance structures differ in what why?

Answer 47

The distibution of electrons across the molecule | pi electrons should be shifted to different atoms

Question 48

Given a polyatomic transition metal, such as V(CO3)2, how do you balance?

Answer 48

Determine the charge on the polyatomic ion first (CO3) = CO3, 2- Since there are 2 of these molecules, it brings the total charge to -4. Than V must have the oxidation state of 4 (+4). Vanadium (IV) carbonate