4.1 BASIC CONCEPTS OF ORGANIC

Question 1

What is organic chemistry?

Answer 1

Organic chemistry is the study of carbon containing compounds

Question 2

Why is carbon so versatile?

Answer 2

Carbon is so versatile because each carbon atom can form four chemical bonds to other atoms. Carbon can form single, double or triple bonds and long carbon chains which can be straight, branched and even ringed. Carbon forms more than 10 million organic compounds.

Question 3

What is aliphatic organic?

Answer 3

Aliphatic contains carbon atoms joined together in straight chains

Question 4

What is alicyclic organic?

Answer 4

Alicyclic contains carbon atoms joined together in a ring that is not aromatic

Question 5

What is aromatic organic?

Answer 5

Aromatic contains one or more benzene ring

Question 6

What is a hydrocarbon?

Answer 6

Hydrocarbons are compounds containing only hydrogen and carbon atoms

Question 7

What are saturated and unsaturated hydrocarbons?

Answer 7

Saturated hydrocarbons contain only single bonds.
Unsaturated hydrocarbons contain at least one multiple carbon bond (double or triple)

Question 8

What are functional groups?

Answer 8

Functional groups are the groups of atoms responsible for the characteristic reactions of a compound

Question 9

What are homologus series?

Answer 9

Homologus series are a series of organic compounds having the same functional group but with each successive member different by CH2, e.g Alkanes

Question 10

What is the general formula?

Answer 10

General formula is the simplest algebraic formula of a member of a homologus series, e.g Alkanes CnH2n+2

Question 11

What is the displayed formula?

Answer 11

Displayed formula shows relative positioning of all the atoms in a molecule and the bonds between them

Question 12

What is the structural formula?

Answer 12

Structural formula shows minimal detail for the arrangement of atoms in a molecule

Question 13

What is the skeletal formula?

Answer 13

The skeletal formula is the simplified organic formula where hydrogen atoms are removed leaving carbon skeleton and functional groups
-a line represents a bond
-intersection between lines represents carbon atoms
-end of line represents -CH3

Question 14

What are alkanes?

Answer 14

Alkanes are saturated hydrocarbons with single bonds
-general formula CnH2n+2

Question 15

What are alkenes?

Answer 15

Alkenes are unsaturated hydrocarbons with double bonds
-general formula CnH2n

Question 16

What are alcohols?

Answer 16

Alcohols have hydroxyl groups (OH)

Question 17

What are carboxylic acids?

Answer 17

Carboxylic acids have carboxyl groups (COOH)

Question 18

Naming alkanes.

Answer 18

To name alkanes:
-find longest carbon chain
-find functional groups
–e.g 3,4 dimethylhexane

Question 19

Naming alicyclic alkanes.

Answer 19

To name alicyclic alkanes:
-prefix cyclo in front of stem to show carbon ring
-same rules applied

Question 20

Naming alkenes.

Answer 20

To name alkenes:
-procedure of alkanes
-position of double bond must be stated if there are more than 4 carbons in longest chain
-functional group must be given the lowest possible locant number

Question 21

Naming alcohols.

Answer 21

To name alcohols:
-procedure of alkanes
-however if another functional group is on the end it becomes the prefix hydroxy-

Question 22

Naming aldehydes.

Answer 22

To name aldehydes:
-same procedure of alkanes
- -al used

Question 23

Naming ketones.

Answer 23

To name ketones:
-same procedure
- -one used
-carbonyl group position required

Question 24

Naming carboxylic acids.

Answer 24

To name carboxylic acids:
-same procedure
- -anoic acid used

Question 25

What are isomers?

Answer 25

Isomers are different compounds with the same molecular formula
-excludes any different arrangements due to molecules rotating as a whole or particular bonds
-more than one type of isomerism can exist in the same molecule
-more carbon atoms = greater the number of possible isomers

Question 26

What is chain isomerism?

Answer 26

Chain isomerism:
-different arrangement of the carbon skeleton
-similar chemical properties
-slightly different physical properties
-more branching = lower boiling point

Question 27

What is positional isomerism?

Answer 27

Positional isomerism:
-same carbon skeleton
-same functional group
-functional group in different position
-similar chemical properties
-slightly different physical properties

Question 28

What is functional group isomerism?

Answer 28

Functional group isomerism:
-different functional group
-different chemical properties
-different physical properties

Question 29

What are stereoisomers?

Answer 29

Stereoisomers have the same molecular formula but different arrangements of atoms in space

Question 30

What is E/Z isomerism?

Answer 30

E/Z isomerism:
-only occurs in compounds with a C=C double bond
-isomerism around double bonds can occur because rotation around the double bond is restricted so groups attached to the carbon atoms are fixed in position relative to one another
-E isomers, H on opposite side
-Z isomers, H on same side

Question 31

E/Z isomerism conditions.

Answer 31

E/Z isomerism must have:
-a C=C double bond
-different groups attached to each carbon atom of the double bond

Question 32

What is cis-trans isomerism?

Answer 32

Cis-trans isomerism:
-special type of E/Z isomerism where one of the groups attached to each carbon on the double bond is hydrogen
-cis isomers, H on same side (Z)
-trans isomers, H on opposite sides of molecule (E)

Question 33

What is the Cahn-Ingold-Prelog nomenclature?

Answer 33

Cahn-Ingold-Prelog nomenclature is when each carbon on a double bond does not have a hydrogen attached
STEP 1- atoms attached to each carbon are assigned either high or low priority bases on their atomic number. higher the atomic number, higher the priority
STEP 2- if higher priority groups attached to each carbon are on the same side it is a Z isomer. if higher priority groups are on opposite sides it is an E isomer.
STEP 3- if two atoms attached to a carbon on the double bond are the same the first point of difference must be found. Group with the highest atomic number at first point of difference is assigned higher priority