Organics 4.1

Question 1

What is IUPAC?

Answer 1

The International Union f Pure and Applied Chemistry, IUPAC, has developed a naming system for organic chemicals - the system of naming compounds is called nomenculture.

Question 2

What is a homologous series?

Answer 2

Families of organic chemiclas are called homologous series. To be members of a homologous series the substances must have the smae functional group and successive members differ onnly by a CH₂ unit.

Question 3

Hydrocarbons are made up of molecule sthat contain only hydrogen atoms and carbon toms. What are aliphatic hydrocarbons?

Answer 3

Aliphatic hydrocarbons - in which the carbon atoms are joined togther in either straight (unbranched) chains or branched chains.

Question 4

Hydrocarbons are made up of molecule sthat contain only hydrogen atoms and carbon toms. What are alicyclic hydrocarbons?

Answer 4

Alicyclic hydrocarbons - in which the carbon satoms are joined togther in either straight (unbranched) chains or branched chains.

Question 5

Hydrocarbons are made up of molecule sthat contain only hydrogen atoms and carbon toms. What are aromatic hydrocarbons?

Answer 5

Aromatic hydrocarbons - in which there is at least one benzene ring in the structure.

Question 6

Define nomenculture.

Answer 6

Nomenculture is the naming system for compounds.

Question 7

Define a homologous series.

Answer 7

A homologous series is a series of organic compounds that have the same functional group with successive members differing by CH₂.

Question 8

Define a saturated compound.

Answer 8

Saturated compounds have only single bonds.

Question 9

Define a functional group.

Answer 9

A functional group is a group of atoms that is responsible for the characteristic reactions of a compound.

Question 10

What is a general formula?

Answer 10

All the compounds in an homologous series share the same general formula. This is the simplest algebraic formula for all the organic compouds in a homologous series and can be used to generate a molecular formula.

Question 11

What is the general formula for an alkane?

Answer 11

C_<em>n</em>H_{2<em>n</em>+2’}

Question 12

What is the general formula for an alkene?

Answer 12

C_nH_{2<em>n</em>’}

Question 13

Whta is the general formula for an alcohol?

Answer 13

C_<em>n</em>H_{2<em>n</em>+1}OH

Question 14

What does a displayed formula show?

Answer 14

The relative positions of all the atoms in a molecule and the bonds between them.

(In a displayed formula, it is important to show all the bonds, even those in functional groups. For example an alcohol group should be shown as -O-H not -OH.

Question 15

What is a structual formula?

Answer 15

A structual formual gives the minimum detail for the arrangement of atoms in a molecule.

Butane would have the structual formula of CH₃(CH₂)₂CH_3.

Question 16

Recap the definitions for a general, structual and displayed formula.

Answer 16

• A general formula is the simplest alegbraic formula for a homologous series.
• A structual formula provides the minimum detail for the arrangement of stoms in a nomlecule.
• A displayed formula shows the relative positions of atoms and the bonds between them.

Question 17

Whta is an empiricle formula?

Answer 17

An empiricle formula shows the smallest whole-number ratio of atoms of the elements in a compound.

Question 18

What 5 steps are required to work out the empiricle formula of an element from the mass of each element in a compound.

Answer 18

1. Change the percentages to masses
2. Calculate the number of moles of each element using amount (moles) = mass (g) / relative atomic mass
3. Divide by the smallest value.
4. Change the ratio to whole numbers
5. Write the formula.

Question 19

What does a molecular formula show?

Answer 19

A molecular formula shows the numbers and types of atoms in a compound.

Question 20

What three-step method generates the molecular formula from the empiricle and molecular mass?

Answer 20

1. Calculate the relative empiricle mass using the empircle formula.
2. Divide the realtive moleclar mass by the empiricle formula mass.
3. Multiply each atom in the empiricle formula by the number calculated in step 2 and write the molecular formula.

Question 21

Define the skeletal formula.

Answer 21

A skeletal formula is a simplified structual formula drawn by removing hydrogen atoms from alky chains.

Question 22

Define unsaturated.

Answer 22

Unsaturated organic chemicalscontain at leats one carbon-carbon double covalent bond.

Question 23

Define hydrocarbons.

Answer 23

Hydrocarbons are compounds that contain only hydrogen atoms and carbon atoms.

Question 24

Define saturated.

Answer 24

Saturated organic chemicals contain only single covalent bonds.

Question 25

What are the different types of isomerism?

Answer 25

• Structual isomers
• Steroeisomers
• Cis-trans isomerism
• E/Z isomerism