Introduction to Organic Chemistry

Question 1

What is a general formula?

Answer 1

An algebraic formula that can describe any member of a family of compounds.

Question 2

What is an empirical formula?

Answer 2

The simplest ratio of atoms of each element in a compound.

Question 3

What is a molecular formula?

Answer 3

The actual number of atoms of each element in a molecule.

Question 4

What is a structural formula?

Answer 4

Shows the atoms carbon by carbon with the attached hydrogens and functional groups.

Question 5

What is a skeletal formula?

Answer 5

Shows the bonds of the carbon skeleton only, with any functional groups. The hydrogen and carbon atoms aren’t drawn.

Question 6

What is a displayed formula?

Answer 6

Shows how all the atoms are arranged, and all the bonds between them.

Question 7

What is a homologous series?

Answer 7

A homologous series is a series of compounds with the same functional group and are represented by the same general formula. They often have similar chemical properties.

Question 8

How would you recognize alkanes?

Answer 8

Prefix/Suffix: -ane
Example: propane CH3CH2CH3

Question 9

How would you recognize branched alkanes?

Answer 9

Prefix/Suffix: alkyl- -ane
Example: methylpropane CH3CH(CH3)CH3

Question 10

How would you recognize alkenes?

Answer 10

Prefix/Suffix: -ene
Example: propene CH2=CHCH3

Question 11

How would you recognize haloalkanes?

Answer 11

Prefix/Suffix: Fluoro- Bromo- Chloro- Iodo- -ane
Example: Chloroethane CH3CH2Cl

Question 12

How would you recognize alcohols?

Answer 12

Prefix/Suffix: -ol
Example: Ethanol CH3CH2OH

Question 13

How would you recognize aldehydes?

Answer 13

Prefix/Suffix: -al
Example: Ethanal CH3CHO

Question 14

How would you recognize ketones?

Answer 14

Prefix/Suffix: -one
Example: propanone CH3COCH3

Question 15

How would you recognize carboxylic acids?

Answer 15

Prefix/Suffix: -oic acid
Example: Ethanoic acid CH3COOH

Question 16

How would you recognize esters?

Answer 16

Prefix/Suffix: alkyl- -oate
Example: Ethyl Ethanoate CH3COOCH2CH3

Question 17

How would you recognize amines?

Answer 17

Prefix/Suffix: -amine
Example: methylamine CH3NH2

Question 18

How would you recognize amides?

Answer 18

Prefix/Suffix: -amide
Example: Ethanamide CH3CONH2

Question 19

How would you recognize acyl chlorides?

Answer 19

Prefix/Suffix: -oyl chloride
Example: Ethanoyl chloride CH3COCl

Question 20

How would you recognize cycloalkanes?

Answer 20

Prefix/Suffix: Cyclo- -ane
Example: Cyclohexane C6H12

Question 21

How would you recognize arenes?

Answer 21

Prefix/Suffix: -benzene (or phenyl-)
Example: methylbenzene C6H5CH3

Question 22

What is the process of naming an organic molecule?

Answer 22

1. count the number of carbon atoms (longest chain)
2. identify the main functional group to get the suffix
3. number all of the branches coming off the longest chain as numbers starting from the functional group’s side.
4. make sure the side chains are mentioned in alphabetical order
5. use di, tri etc. if there is more than one identical side chain or functional groups

Question 23

What are the IUPAC Rules?

Answer 23

The international language for naming chemical compounds

Question 24

What are mechanisms?

Answer 24

Mechanisms are diagrams that break reactions down into individual stages. They show how molecules react together by using curly arrows to show which bonds are made or broken.
This is shown through curly arrows which show where a pair of electrons goes during a reaction.

Question 25

What are isomers?

Answer 25

Isomers are the same substance with the same molecular formula, but a different structural formula. There are two different types of isomers: structural isomers and stereoisomers.

Question 26

What are the three types of structural isomers?

Answer 26

Chain isomers, Positional isomers, and Functional group isomers.

Question 27

What are chain isomers?

Answer 27

Chain isomers have different arrangements of the carbon skeleton. Some are straight chains and others are branched in different ways.
For example: butane and methylpropane

Question 28

What are position isomers?

Answer 28

Position isomers have the same skeleton and the same atoms or groups of atoms attached. The difference is that the atoms or groups of atoms are attached to a different carbon atom.
For example: 1-chlorobutane and 2-chlorobutane

Question 29

What are functional group isomers?

Answer 29

Functional group isomers have the same atoms arranged into different functional groups.
For example: hex-1-ene and Cyclohexane

Question 30

What are stereoisomers?

Answer 30

Stereoisomers have the same structural formula but a different arrangement in space.
Double bonds can’t rotate which leads to a stereoisomerism called E/Z isomerism

Question 31

Why do alkenes show E/Z isomerism?

Answer 31

Alkenes have restricted rotation around their carbon-carbon double bonds. This means that if both of the double-bond carbons have different atoms or groups attached to them, the arrangement of those groups around the double bond can change to create two stereoisomers. One of these is the E-isomer and one is the Z-isomer. The Z isomer has the same groups either both above or both below the double bond while the E isomer has the same groups but across the double bond in diagonals. E-But-2-ene becomes Z-But-2-ene

Question 32

What are the Cahn-Ingold-Prelog Priority Rules?

Answer 32

When having a C=C bond with 3 or 4 different groups you use these rules.
1) assign a priority to the two atoms attached to each carbon in the double bond ie 1 and 2 (the atom with the higher atomic number on each carbon is given priority, e.g. F is higher than H)
2) to work out which isomer group you have, you need to work out how the higher-priority groups are arranged

Question 33

What is a nucleophile?

Answer 33

A nucleophile is a reactant that donates a pair of electrons to form a new covalent bond.

Question 34

What is an electrophile?

Answer 34

An electrophile is a chemical species that is attracted to electrons.