organic chem

Question 1

why is carbon important

Answer 1

it has 4 valence electrons = 4 bonds, and can bond with itself or others
Bonds are strong, non-polar, and geometrically flexible

Question 2

what are the rules to line drawing

Answer 2

Carbon (C) -> Shown as ends or bends of lines

Hydrogen (H) -> not shown if bonded to carbon

other atoms -> must be drawn explicitly

Question 3

wedges

Answer 3

bonds coming out of the page

Question 4

dashes

Answer 4

bonds going into the page

Question 5

what is a molecular formula

Answer 5

every atom is accounted for properly ie c_2h_2 instead of 2CH

Question 6

What Is a Functional Group?

Answer 6

A functional group is a specific group of atoms within a molecule that determines how that molecule will react chemically.

Question 7

Carbon-Only Functional Groups

Answer 7

These are groups made up of just carbon (and hydrogen):

Question 8

Alkene

Answer 8

C=C double bond

Causes different reactivity compared to single bonds

Ends in “-ene” when naming

Geometry = trigonal planar at the double bond

Question 9

Alkyne

Answer 9

C≡C triple bond Very reactive, linear geometry

Ends in “-yne”

Question 10

Arene (Aromatic Ring)

Answer 10

Alternating single and double bonds in a ring

Electrons are delocalised across the ring

Called aromatic compounds

Question 11

naming Alkanes

Answer 11

Find the longest continuous carbon chain
→ This becomes the base name (e.g., methane, ethane, propane…)

Number the chain from the end closest to any substituent (side group like –CH₃)

Identify and name branches

One-carbon branch = methyl

Two-carbon = ethyl, etc.

Use numbers to show position of branches

e.g., 2-methylpentane = 5-carbon chain with a methyl on carbon 2

Alphabetise side groups if more than one (ethyl before methyl)

Question 12

Alkanes

Answer 12

single bond

Question 13

branched alkanes

Answer 13

find the longest chain
use the ‘thyle’ to indicate attachments and a number to show their position

Question 14

Cycloalkanes

Answer 14

These are rings made from alkanes:

3-carbon ring → cyclopropane

4-carbon → cyclobutane

5-carbon → cyclopentane, etc.

Rings introduce strain due to forced bond angles, especially in small rings.

Question 15

‘adiene’

Answer 15

2 double bonds

Question 16

Isomers

Answer 16

⚖️ Isomers = Compounds with the same molecular formula but different structures

Question 17

Constitutional (Structural) Isomers

Answer 17

Atoms are connected in different ways

Question 18

Stereoisomers

Answer 18

Same atom-to-atom connections, but different spatial (3D) arrangements

🔹 Two types:

Enantiomers = Mirror images (think left/right hands)

Diastereomers = Not mirror images (e.g. cis/trans, E/Z)

Question 19

Conformational Isomers

Answer 19

Same molecule, but rotated around a single bond

Happens constantly — not a new molecule, just a new “pose”

Question 20

how to remember the prefix

Answer 20

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