Organic Chemistry

Question 1

How many valence electrons does carbon have?

Answer 1

4

Question 2

What is carbons electron configuration? And its valence shell configuration?

Answer 2

1s2, 2s2, 2p2

Valence shell = 2s2, 2p2

Question 3

What is carbons electronegativity number?

Answer 3

2.5

Question 4

Which element has the highest electronegativity and what is it?

Answer 4

Fluorine

4

Question 5

What bond type does carbon have? What are the pros of this?

Answer 5

4 Covalent (between atoms with equal negativity)
And 4 polar covalent (atoms with differing electronegativity) 
Means carbon can bond to other atoms in a lot of different combinations and form many different types of structures

Question 6

What is the empirical formula?

Answer 6

The simplest while number ratio of elements

Question 7

What is the molecular formula?

Answer 7

The actual number of atoms of each element

Question 8

What is the structural formula?

Answer 8

Minimal detail for an unambiguous structure

Writes out every compound in molecule

Question 9

What is the displayed formula

Answer 9

Relative placing of atoms and bonds between them (diagram)

Question 10

What is the skeletal formula

Answer 10

The carbon skeleton and functional groups only (very basic diagram)

Question 11

Describe sigma bonds

Answer 11

When 2 orbitals overlap as 2 atoms approach
End to end overlap bond formed = sigma
Electrons of one atom attracted to nucleus of the other
Attraction continues until repulsion between the 2 nuclei outweighs it

Question 12

What’s is hybridisation?

Answer 12

Combining 2+ atomic orbitals from the same atom to create new orbitals

Question 13

Describe sp3 hybridisation

Answer 13

S and p orbitals are mixed to form hybrid orbitals

1 s and 3 p orbitals are mixed (a 2s electron prompted into empty 2p orbital = 4 unpaired electrons)

Question 14

Describe sp2 hybridisation

Answer 14

One s orbital and two p orbitals hybridise and form sigma bonds (one p orbital left over)
Sp2 hybridisation gives a bond angle of 121.3 degrees
The 2 pure p orbitals of the 2 carbon atoms can overlap sideways to form a pi bond

Question 15

What is a pi bond

Answer 15

covalent chemical bonds where two lobes of an orbital on one atom overlap two lobes of an orbital on another atom and this overlap occurs laterally

Question 16

Describe benzene structure

Answer 16

• planar molecule
• each carbon is sp2 hybridised
• 6 electrons in pure p orbitals capable of overlapping
• get delocalisation over the ring

Question 17

Describe sp hybridisation

Answer 17

• 2 pure p orbitals left over per carbon atom = 2 pi bonds
• 1s atom and 1p atom hybridise
• each carbon atom forms 2 sigma bonds and 2 pi bonds

Question 18

What are the properties of organic compounds? (4)

Answer 18

• physical and chemical behaviour heavily influenced by molecules polarity
• most are not soluble with water
• somewhat soluble if have oxygen or nitrogen atoms: electronegative atoms form hydrogen bonds with the water
• many undergo combustion and burn vigorously in air

Question 19

Describe polarity of organic molecules

Answer 19

• covalent bond between 2 carbons non polar because electrons shared equally
• most elements found in organic compounds more electronegative than carbon (except H)
• polarity of molecule determined by polarity of bonds and structure
• bond can be polar but molecule non polar if has symmetrical arrangement of polar bonds that cancels out the dipoles.

Question 20

What are the 2 classes of organic compounds

Answer 20

-aromatic
Contains cyclic conjugated (alternating double and single bonds) double bond system with 4n + 2pi electrons

-aliphatic
All other compounds without a ring system

Question 21

Why do we have classes of organic compounds

Answer 21

• there are millions of different types
• characteristic structural features ‘functional groups’
• allows to classify and name compounds within families
• identification of functional groups helps to predict reactivity of a compound

Question 22

Oxidation of carbon

Answer 22

They form additional bonds to oxygen

Question 23

Reduction of carbon

Answer 23

They form additional bonds to hydrogen

Question 24

Substitution

Answer 24

Exchange of one atom in a molecule with another atom/group of atoms

Question 25

Elimination

Answer 25

Single reactant split into 2 products

Question 26

Addition

Answer 26

2 reactants add together to form single product

Question 27

Homolytic reaction of carbon compound

Answer 27

• 1 electron transferred to each atom

- formation of radicals

Question 28

Heterolytic reaction of carbon compound

Answer 28

• 2 electrons transferred to another atom

- formation of ions

Question 29

What is a radical?

Answer 29

Atom containing at least 1 unpaired electron