3.1 Intro to Organic

Question 1

Define empirical formula

Answer 1

Simplest whole number ratio of atoms in a molecule.

Question 2

Define molecular formula

Answer 2

Gives the actual number of different elements in a molecule.

Question 3

Define displayed formula

Answer 3

Shows every atom and bond in a molecule.

Question 4

Define structural formula

Answer 4

Shows arrangement of atoms in a molecule without showing every bond.

Question 5

Define skeletal formula

Answer 5

Drawn lines with each vertex being a carbon atom - presumes all unspecified bonds as C-H.

Question 6

Define structural isomerism

Answer 6

When molecules have the same molecular formula but a different structural formula.

Question 7

What is positional isomerism ?

Answer 7

When the functional group is attached or located at a different place on the chain.

Question 8

What is functional group isomerism ?

Answer 8

When molecules have the same atoms but a different functional group due to their structure.

Question 9

What is chain isomerism ?

Answer 9

When hydrocarbon chains are organised differently eg having branched chains.

Question 10

Define stereoisomerism

Answer 10

When molecules have the same structural and molecular formula but are arranged differently in space.

Question 11

What are E/Z Isomers ? (2)
What determines E/Z isomers ?

Answer 11

•E/Z isomerism only occurs in molecules which have C=C as it provides limited rotation
•This lack of rotation means that the groups attached to the carbons are not the same if one is positioned up and one is positioned down

•If the two groups with the highest mass are on the same side of the double bond it is a Z isomer
•If they are on different sides it’s a E isomer.
•(Different sides)