Organic Chemistry and Carbon Bonding

Question 1

What is the historical definition of organic chemistry?

Answer 1

The chemistry of living things
-compounds obtained from living organisms were thought to poppies vital force that differentiated them from inorganic chemicals

Question 2

Who synthesised urea from ammonium cyanate?

Answer 2

Wohler

Question 3

What was synthesised in 1958?

Answer 3

Synthesis of Perkin’s mauve

Question 4

What is the modern definition of organic chemistry?

Answer 4

The chemistry of compounds of carbon

Question 5

What forms can organic compounds come in?

Answer 5

• Colourless, coloured
• Gases, liquids or solds
• Waxes
• Plastics
• Odorous or odourless

Question 6

Finish the sentence:

If we want to understand life processes on a molecular level we nee to understand the….

Answer 6

Structure of organic molecules

Question 7

What do the properties of organic molecules depends on?

Answer 7

Structure of molecule

Question 8

What is a deoxyribonucleic acid (DNA) relating to organic chemistry?

Answer 8

Carbon forms part of the sugar phosphate backbone and the attached bases

Question 9

What is protein relating to organic chemistry?

Answer 9

Carbon forms part of the peptide backbone and attached side chains

Question 10

What is fatty acids to organic chemistry?

Answer 10

Carbon, hydrogen and oxygen containing molecules (Saturated - no double bonds or unsaturated - double C=C bonds)

Question 11

How are proteins and fatty acids made up by?

Answer 11

Biologically catalysed chemical reactions

Question 12

Fill in the sentence:

Carbon has the ability to bind …. to other elements and for strong bonds with its …..

Answer 12

1) Strongly

2) Itself

Question 13

What does carbon have a rare tendency to do?

Answer 13

Catenate

Question 14

What is meant by catenate?

Answer 14

Form chains of carbon atoms

Question 15

What does the carbon allow being able to catenate?

Answer 15

Allows a vast range of structure and therefor properties

Question 16

What is carbons electron configuration?

Answer 16

1s2 2s2 2p2

Question 17

What does carbon require to have a full valance?

Answer 17

4 extra electrons

Question 18

What are the Lewis structures?

Answer 18

Dot and cross structures to display covalent bonding between molecules

Question 19

What is wrong with the Lewis structure?

Answer 19

Does not attempt to explain the geometry of molecules, how bonds are formed or how electrons are shared between atoms

Question 20

Define atomic orbital:

Answer 20

Region within an atom which can hold up to two electrons with opposite spins

Question 21

What are the 4 meaningful types of orbitals?

Answer 21

s, p, d or f

Question 22

Finish the sentence:

Each orbital has a…

Answer 22

specific shape

Question 23

What are orbitals arranged into?

Answer 23

Groups of similar energies

Question 24

What is principle quantum number (n)?

Answer 24

Related to the energy of an orbital

Question 25

What is molecular orbital theory?

Answer 25

Two half-filled atomic orbitals combine to give a single or s-bond (sigma) consisting of two s-molecular orbitals

Question 26

What does a double bond consist of?

Answer 26

s-bond and a p-bond

Question 27

What does a molecular orbitals with double bonds form?

Answer 27

-Two p orbitals can overlap end-on, to form two s-molecular orbitals
OR
-Two p orbitals can overlap side-on, to form two p-molecular orbitals

Question 28

What is the ground state?

Answer 28

The lowest state

Question 29

If a carbon was to remain at a ground stat in a molecule it must:

Answer 29

• Share two electrons

- Only have 6 electrons in its valance orbital

Question 30

1s atomic orbital + 2s atomic orbital =

Answer 30

Have correct symmetry to form sigma bond

Question 31

1s atomic orbital + 2px orbital =

Answer 31

Have the correct symmetry to form a sigma bond

Question 32

1s atomic orbital + 2py orbital =

Answer 32

Do no have the correct symmetry

Question 33

What is the hybrid model?

Answer 33

Mathematically, energetically favoured in the resting molecular compound

Question 34

What is orbital hybridisation?

Answer 34

2s orbital and 2p orbitals are mixed to give sp3 hybrid orbitals

Question 35

What does it mean if orbital hybridisation happens?

Answer 35

Carbon can form 4 covalent bonds to fulfil the octet rule

Question 36

What happens in methane relating to hybrid orbitals?

Answer 36

Sp3 orbitals mixes with hydrogen s orbital to form 4 sigma bonds to four hydrogen atoms

Question 37

What is the bond angle in methane?

Answer 37

109.5 bond angle

Question 38

Why does a tetrahedral arrangement occur?

Answer 38

Mutual repulsion will push the molecular orbitals as far apart as possible

Question 39

Describe ethane in relation to hybrid orbitals:

Answer 39

• Three sp3 orbitals mix with the s orbitals of three hydrogen atoms to from three sigma bonds
• One sp3 orbital mixes with an sp3 orbital from second carbon atom forming c-c sigma bond

Question 40

How do you achieve double carbon bond?

Answer 40

Having three sp2 hybrid orbitals and one unhybridized p orbital

Question 41

What is an sp2 orbital hybridisation?

Answer 41

One s orbital and two p orbitals

Question 42

Describe ethene in terms of orbital hybridisation:

Answer 42

Each carbon atom forms three sigma bonds:

• 2 to two hydrogen atoms
• 1 to second carbon atom (causing an overlap of sp2)

Each carbon atom forms a pie bond to the second carbon atom (overlap of unhybridized p orbitals)

Question 43

Which bond is stronger sigma or pie bond?

Answer 43

Sigma

Question 44

Describe sigma bond:

Answer 44

• End-on overlap (more effective)
• 346 Kjmol^-1
• Stronger
• Less reactive

Question 45

Describe pie bond:

Answer 45

• Edgewise overlap (less effective)
• 252 KJmol^-1
• Weaker
• More reactive

Question 46

How do you achieve a triple carbon bond?

Answer 46

2x sp hybrid orbitals
2x unhybridized orbitals
p orbital define the geometry around the carbon atom and the others try and position as far as possible
-one sigma bond
-2 pie bonds (overlap of unhybridised p-orbitals)