Organic Chemistry

Question 1

Since a proton is positively+ charged, what does an atom need to stay electrically neutral?

Answer 1

The same number of electrons, wich are negatively- charged

Question 2

How does an atom become an Ion?

Answer 2

If an atom has more or fever electrons than protons

!Becomes electrically charged!

Question 3

How does an atom become an Anion?

Answer 3

When an atom has more electrons than protons in it’s nucleus

!Becomes a negatively- charged ion!

Question 4

How does an atom become an Cation?

Answer 4

When an atom has fewer electrons than protons

!Becomes a positively+ charged ion!

Question 5

How many electrons can the first shell, wich is closest to the nucleus hold?

Answer 5

2

The first shell has the lowest energy

Question 6

How many electrons can the second and third shell hold?

Answer 6

8 & 18

Where the 2nd shell holds 8 and 3rd holds 18

Question 7

What are electron shells further subdivided into?

Answer 7

Orbitals

Aka the actual location where an electron is found in a shell

Even though you can never know exactly where an electron is, you can know the region of space — The electrons orbital

!To explain further : A shell indicates the energy level of an electron, the orbital is the location of the electron!

Question 8

What are the two atomic orbitals in Organic Chemistry?

Answer 8

s & p

Personally I remember these by thinking S = circle and P = Pointy

Question 9

What do electrons do to eachother?

Answer 9

Repel

Electrons want to get as far away as possible from eachother

Question 10

Define

Valence electrons

Answer 10

Electrons in the outermost shell of an atom

!For bonding valence electrons are important!

The number of valence electrons are represented by the number of dots around the atom

Question 11

Define

Covalent Bond

Answer 11

A bond where electrons are shared between two atoms

Question 12

Explain

Polar covalent

Answer 12

Polar covalent = electronegativity difference is smaller, aka the electrons are not shared equally

The separation in a polar covalent bond is called a dipole movement

Question 13

Explain

Name and function of the arrow

Answer 13

The dipole vector, used to show the direction of dipole moment (separation of charge)

!Prediction of dipole moment can help understand molecular reactions!

The head of the arrow shows the direction of the partial negative- charge, while the tail shows the direction of the partial positive+ charge

Question 14

Explain

VSEPR

Answer 14

Stands for “Valence Shell Electron Pair Repulsion”

Predicts the approximate geometry of bonds around an atom

Question 15

Explain

Hybridized orbitals

Answer 15

Multiple different orbitals combined making new orbitals

Eg. Three 2p orbitals + 2s orbital = sp3

Question 16

Covalent bonds occur when the orbitals of bonding atoms overlap each other, what are the two types of covalent bonds?

Answer 16

Sigma bonds = bonds where orbital overlap occurs between the two bonding nuclei

Pi bonds = bonds where orbital overlap occurs above and below the nuclei

Question 17

____ is the only atom that does not hybridize it’s orbials for bonding

Answer 17

Hydrogen

Question 18

In a Lewis structure, nonbonding electrons are indicated with ____ on the atom?

Answer 18

Dots

Question 19

What is the first thing you should be able to identify in a Lewis structure?

Answer 19

Which atoms have formal charge

Question 20

Define

Atom’s valency

Answer 20

Number of bonds around a neutral atom

Question 21

What is a another name for a Lewis Structure?

Answer 21

Kekulé structure

Question 22

Define

Lewis Structure

Answer 22

Draws out all the bonds in a molecule

Lone pairs on atoms may not be shown

Formal charges are always shown

Question 23

Explain

Condensed Structure

Answer 23

Bonds between Carbon & Hydrogen are not shown, instead each Carbon and the attached Hydrogen are grouped together into clusters

Eg. CH2 or CH3

These clusters are written in a chain that show the connectivity between the Carbons

Question 24

Explain

Line Bond structure

Answer 24

Where each node (point) is assumed to be a carbon atom

The ends (tips) of the lines are also assumed to be carbon atoms

Note that “R” stands for rest of the molecule

Question 25

# True or False All hydrogens (H) attached to non-carbon elements must be shown on a line bond structure

Answer 25

True

Question 26

# True or False All atoms are presumed to be neutral (+-) unless a charge is shown

Answer 26

True

Question 27

# True or False Structures can be drawn using all three styles | Full Lewis Structure, Line-bond structure & Condensed structure

Answer 27

True

Question 28

What are the 6 main arrows used in Organic Chemistry?

Answer 28

## Footnote Arrows are always drawn from electrons toward where they are going

Question 29

# Explain Rules for Resonance Structures

Answer 29

* **Atoms are fixed and cannot move** - the purpose of resonance structures is to account for alternative locations of electrons, so all atoms stay in fixed positions * **Only lone-pair electrons and pi electrons can move** - single bonds stay put, but double and triple bonds can move * **The octet rule cannot break** - the sum of an atom's lone pairs and bonds cannot be greater than 4 for second-row elements