Chpt 1: Structure and Bonding in Organic Molecules

Question 1

what is organic chemistry the study of?

Answer 1

carbon and it’s compounds/molecules

Question 2

what do we use organic chemistry for?

Answer 2

to understand chemicals produced by living things and to make things like drugs, plastics, food products, pesticides, petroleum products, etc

Question 3

why is carbon so important in/to living things?

Answer 3

it’s a principle component in stuff like fat, sugars, protein, and nucleic acid

Question 4

what are functional groups?

Answer 4

groups of atoms within a molecule that give the molecule its characteristic bonding/reactivity behavior

Question 5

how are molecular structure and reactivity related?

Answer 5

the structure of a molecule determines the reactions that it can undergo

Question 6

What is ionization potential?

Answer 6

The energy involved in losing an electron

Question 7

What is electron affinity?

Answer 7

The energy involved in gaining an electron

Question 8

What is electrostatic attraction?

Answer 8

The energy involved in bringing things together

Question 9

what range of charge separations are considered to be polar?

Answer 9

ranges between 0.3 and 2.0

Question 10

what does it mean to say that a molecule/lewis structure is charge separated?

Answer 10

it means that the electrons are not evenly distributed around the atoms

usually bc of differences in atom electronegativity

Question 11

what 3 situations break the octet rule?

Answer 11

when a molecule has odd number of electrons

when a compound (usually from period 2) has too few valence electrons

when a compound contains elements bigger than phosphorus/period 2

Question 12

what does it mean to say that a charge in a resonance structure is delocalized?

Answer 12

that the charge on the molecule is spread out in space, across the various resonance structures

Question 13

How does one resonance structure for a molecule compare to another resonance structure for the same molecule?

Answer 13

Both have the same placement of atoms and the same overall formal charge but the placement of the electrons is different

Question 14

When you’re writing resonance structures, are you allowed to change which atoms are bonded to which other atoms?

Answer 14

No. In each resonance structure, the same atoms must be bonded to each other in all structures

The only difference between the structures is the arrangement of the electrons

Question 15

what properties determine how much a given resonance structure contributes to a resonance hybrid?

Answer 15

1. number of octets (more octets, more contribution)
2. degree to which electrons are positioned around the most electronegative atom (more electrons on the electronegative parts, more contribution)
3. degree of neutralness (less charge separation, less dipole character, more contribution)

Question 16

what’s the difference between and atomic orbital and molecular orbital?

Answer 16

atomic orbitals describe the wave functions inhabited by the electrons on a given atom.

molecular orbitals describe the OVERLAPPING of electron clouds between 2 separate atoms

Question 17

what is a substituent?

Answer 17

an atom or group of atoms which replaces one or more hydrogen atoms on the parent chain of a hydrocarbon

Question 18

what is the bond angle for single/sigma bonds in a hybridized carbon?

Answer 18

109.5 degrees tetrahedral

gives the zig zag/tetrahedral shape when all four bonds are hybridized

Question 19

what is the bond angle for double (pi) bonds in a hybridized carbon?

Answer 19

120 degrees trigonal planar

looks similar to sigma bonds in line structure

Question 20

what is the bond angle for triple (sigma, pi, pi) bonds in a hybridized carbon?

Answer 20

180 degrees linear

makes a straight line on the line structure

Question 21

what is an isomer?

Answer 21

what you call it when a molecules have the same molecular formula but differ from one another in some specific way

exp. 2 molecules with the same formula but with the atoms connected differently

Question 22

how many types of isomers are there?

Answer 22

at least 2

Question 23

what is a constitutional isomer?

Answer 23

an isomer that differs from other molecules (with the same molecular formula) by the way its atoms are attached

Question 24

in resonance structures, do electrons ever jump from one atom to a completely different atom?

Answer 24

no. They have to be shared with/moved about the original atom that they belong to

Question 25

in resonance structures, which atoms can get away with having less than an octet?

Answer 25

Carbon

A structure whose carbon has less than an octet is still considered valid

Question 26

can you move/adjust single bonds to make resonance structures?

Answer 26

No. You can only adjust double/pi bonds (because these are in the pi system)

Adjusting single bonds would change the connectivity of the molecule

Question 27

Which bond is weaker: sigma bond or pi bond?

Answer 27

Pi bond

The ‘head on’ sigma bond is more stable/less reactive than the ‘side on’ pi bond, which is less stable/more rective

Question 28

Which bond has more energy: sigma bonds or pi ponds?

Answer 28

Pi bonds

They come from regular p orbitals which have higher energy that s and sp orbitals; the higher energy is what makes them more reactive

Question 29

what are the steps for drawing constitutional/structural isomers?

Answer 29

1. determine the DOU
2. draw the carbon chain
3. add the other non carbon components as substituents (configured as functional groups if you can)
4. move the components around
5. Remove a carbon from the end of the chain, and add it back as a substituent
6. move the other components around
7. repeat and so on and so forth