OChem Fundamentals

Question 1

Hydrocarbons: types

Answer 1

Alkanes (butane)
Cycloalkanes (cyclopropane)
Alkenes (propene)
Alkynes (acetylene)
Aromatic (toluene)

Question 2

Hydrocarbons: definition

Answer 2

Compounds consisting of only carbon and hydrogen and can either be either aliphatic or aromatic.

Question 3

Aliphatic

Answer 3

chains of carbon atoms

Question 4

Aromatic

Answer 4

Rings of carbon atoms with delocalized electrons

Question 5

2 types of aliphatic hydrocarbons

Answer 5

saturated:
- each carbon has the max number of hydrogen atoms
- each carbon is saturated with hydrogen.

unsaturated:
- each carbon has less than the max number of hydrogen atoms
- this implies a double bond must exist.

Question 6

Condensed structural formula

Answer 6

All of the atoms are written out

ex. CH3CH(CH3)CH3

Parentheses around a group show that it is attached to the carbon atom on its left.

Question 7

Line structural formula

Answer 7

A chain of carbon atoms as a zigzag line. Do not need to show the C-H bonds.

Question 8

Alkanes specifics

Answer 8

• all single bonds.
• each carbon is sp^3
• each carbon is tetrahedral
• form single chain
• names end in -ane

Question 9

How to name alkanes?

Answer 9

Combine a prefix denoting the number of carbon atoms with the suffix -ane

Question 10

What is the prefix for ring structures?

Answer 10

cyclo-

Question 11

alkANES
vs
alkENES
vs
alkYNES

Answer 11

alkANES:
- all single bonds
- all sp^3 C
- names end in -ane

alkENES:
- unsaturated
- at least one C=C double bond
- trigonal planar

alkYNES:
- unsaturated
- at least one triple bond
- linear

Question 12

alkENES specifics

Answer 12

alkENES:
- unsaturated
- at least one C=C double bond
-sp^2 carbons
- TRIGONAL PLANAR
- names end in -ene

Question 13

alkYNES specifics

Answer 13

alkYNES:
- unsaturated
- at least on triple bond
- sp carbons
- linear
- name ends in -yne

Question 14

What is a substituent?

Answer 14

A substituent is an atom or group of atoms that replaces a hydrogen atom in a hydrocarbon chain.

Question 15

How to name an organic molecule

Answer 15

1. Find the longest continuous chain of carbon atoms. The number of carbons makes the base name of the molecule.
   - If 2 have the same length, choose the one with more substituents.
2. Number the longest chain starting from the end closest to a substituent.
3. Identify and name substituents.
   - replace -ane with -yl.
4. If multiple substituent, number separately and list alphabetically.
   - Use prefixes for identical groups. Ex, di, tri, tetra, etc. In addition, add the number before the carbon number.
   ex. 2,2-Dimethylbutane
5. Identify and name functional groups

Notes:
- numbers followed by a hyphen
- write as one continuous word

Question 16

How to name alkenes and alkynes

Answer 16

1. The parent chain must include ALL double and triple bonds, even if a longer chain exists.
   - The parent chain must include all double and triple bonds, even if a longer chain exists.
   - The base name is determined by the number of carbons (meth-, eth-, prop-, but-, pent-, hex-, etc.)
   - The suffix “-ene” is used for alkenes (C=C) and “-yne” for alkynes (C≡C).
   - If both types of bonds are present, “-enyne” is used.
2. Number the chain, giving the lowest possible numbers to the multiple bonds
   - Number the carbon chain so that the first multiple bond (either double or triple) gets the lowest possible number.
   - If there’s a tie, the double bond (-ene) gets priority over the triple bond (-yne).
3. Indicate the Position of Each Multiple Bond
   - The position of each double/triple bond is indicated using the lowest-numbered carbon in the bond.
   - If multiple double or triple bonds exist, use di-, tri-, tetra- before “-ene” or “-yne”.
4. Use “-enyne” If the Molecule Contains Both Double and Triple Bonds
5. Add Substituents and Functional Groups (if any)
   - Name and number substituents normally, listing them in alphabetical order.
   - Functional groups take priority over multiple bonds, changing the suffix of the base name.

Question 17

2 Main Isomer Types

Answer 17

Structural isomers and stereoisomers

Question 18

structural isomers

Answer 18

Compounds with the same molecular formula but different connectivity of atoms, resulting in different structures and properties.

Question 19

Stereoisomers

Answer 19

Molecules with the same molecular formula and connectivity but different spatial arrangements of atoms.
- They include geometrical (cis/trans) isomers and optical (enantiomers) isomers.

Question 20

How to draw structural isomers

Answer 20

1. Determine the Molecular Formula
   - Identify the total number of carbon (C), hydrogen (H), and other elements in the given compound.
2. Find the Parent Chain (Longest Carbon Chain)
   - The longest continuous chain of carbon atoms serves as the base structure.
   - Start by drawing the straight-chain (normal) structure.
3. Rearrange Carbon Atoms to Form Different Chains
   - Move carbon atoms to different positions to create branched structures. Preferably terminal carbons.
   - Keep the same number of total carbon and hydrogen atoms.
4. Place Functional Groups in Different Positions (If Any)
   - If the molecule has functional groups (e.g., -OH, -Cl, -Br, -NH₂), try attaching them to different carbon atoms.
5. Check for Multiple Bonds (Alkenes and Alkynes)
   - If there are double (-C=C-) or triple (-C≡C-) bonds, place them in different positions.
6. Ensure No Duplicates
   - Verify that each structure is unique (not just rotated versions of the same structure).

Question 21

Stereoisomers: 2 types

Answer 21

Geometric isomers and Optical isomers

Question 22

Geometrical isomers

Answer 22

• type of stereoisomer where molecules have the same molecular formula and same connectivity of atoms, but differ in the spatial arrangement of groups around a rigid structure, such as a double bond (C=C) or a ring system.
• These are commonly known as cis-trans isomers.

Question 23

Optical isomers

Answer 23

• Enantiomers (mirror images) that have identical chemical properties, except when they react with other chiral compounds.
• If a chiral molecule rotates light clockwise, then its mirror-image rotates it counterclockwise.

Question 24

aromatic compounds

Answer 24

aka arenes
contain an aromatic ring, usually the six-membered ring of benzene

Question 25

Arenes nomenclature

Answer 25

- When the benzene ring is a substituent, it is called a phenyl group. - In general, aromatic hydrocarbon groups are called aryl groups. Step 1: Identify the Parent Structure - If benzene is the main structure, name it as a benzene derivative (e.g., toluene, phenol). - If benzene is attached to a longer carbon chain, name it as a phenyl (-C₆H₅) substituent. Step 2: Number the Ring for Disubstituted Benzenes - If there are two substituents, use the prefix system: - Ortho- (o-) → Substituents at 1,2- positions (adjacent). - Meta- (m-) → Substituents at 1,3- positions (one carbon apart). - Para- (p-) → Substituents at 1,4- positions (opposite sides). Step 3: Name Multi-Substituted Benzene Rings - If three or more substituents are present: - Number the benzene ring so that the first substituent gets the lowest possible number. - List substituents in alphabetical order, ignoring prefixes like di-, tri-. Step 4: Name Benzene as a Substituent (Phenyl & Benzyl Groups) - Use "phenyl-" (-C₆H₅) when benzene is attached to a non-aromatic system. - Use "benzyl-" (-C₆H₅CH₂) when benzene is attached via a CH₂ bridge. Step 5: Special Names for Fused Aromatic Rings - When multiple benzene rings are fused together, special names apply.

Question 26

Common arene names C6H5OH C6H5CH3 C6H5NH2

Answer 26

C6H5OH: phenol C6H5CH3: toluene C6H5NH2: aniline

Question 27

special fused benzene ring names

Answer 27

Two fused benzene rings: Naphthalene (C₁₀H₈) Three linear benzene rings: Anthracene (C₁₄H₁₀) Three bent benzene rings: Phenanthrene (C₁₄H₁₀)

Question 28

Carbon prefixes 1-12

Answer 28

1: meth- 2: eth- 3: prop- 4: but- 5: pent- 6: hex- 7: hept- 8: oct- 9: non- 10: dec- 11: undec- 12: dodec-

Question 29

Common arene names

Answer 29

benzene + OH sub: phenol benzene + CH3 sub: toluene benzene + NH2 sub: aniline benzene + (CH3)2 @ 1,3 sub: m-xylene

Question 29

what to remember when doing radioactive decay?

Answer 29

no matter what, use the calculator, even if it's +1, -1. ALWAYS TRIPLE CHECK. U ARE TIRED AND NERVOUS.

Question 30

All radiation types, symbols, and what they do

Answer 30

alpha: carries away 2 protons, 4/2α beta: loss of a B particle converts a neutron to a proton 0/-1e electron capture: turns a proton into a neutron 0/-1e positron emission: converts a proton to a neutron by shrugging off the positive charge. 0/+1e

Question 31

Drawing organic species:

Answer 31

1) IS IT CYCLO? PLEASE

Question 32

when asking for the enthalpy change from point a to point b, what does it mean?

Answer 32

the name of the enthalpy change. ex: enthalpy of fusion.