Organic Chemistry

Question 1

What are fractions?

Answer 1

Mixtures of hydrocarbons with similar boiling points, separated by fractional distillation.

Question 2

What is distillation?

Answer 2

A process used to separate mixtures.

Question 3

What are the types of distillation?

Answer 3

Simple distillation - Separating out a liquid from a solution. Fractional distillation - Separating out a mixture of liquids.

Question 4

What is a mixture?

Answer 4

Two or more substances not chemically bonded together.

Question 5

What is a hydrocarbon?

Answer 5

A compound made up of only hydrogen and carbon atoms.

Question 6

What is a homologous series?

Answer 6

A series of compounds that have the same general formula and the same properties. They differ by one CH2 group. (e.g. Alkanes)

Question 7

What are alkanes?

Answer 7

A homologous series of hydrocarbons with the general formula of C_nH_2n+2, and only have single bonds.

Question 8

Define saturated (in relation to hydrocarbons).

Answer 8

Containing only single bonds (maximum number of hydrogens bound to the carbon)

Question 9

Define molecular formula.

Answer 9

Formula that shows the number of each type of atom within a compound. (e.g. C2H6)

Question 10

What are alkenes?

Answer 10

Hydrocarbons with the general formula C_nH_2n and they contain a carbon to carbon double bond.

Question 11

Are alkenes saturated?

Answer 11

No, as they have a double bond.

Question 12

What is the prefix of the first five hydrocarbons?

Answer 12

Meth, Eth, Prop, But, Pent

Question 13

What happens when you add bromine water to an alkene and alkane?

Answer 13

Question 14

What is the reaction between an alkene/alkane and bromine water called?

Answer 14

Addition Reaction

Question 15

What state are the hydrocarbons in when they enter the distillation collumn?

Answer 15

Gas

Question 16

What ensures there can be fractional distallation in the column?

Answer 16

Temperature Gradient

Question 17

What happens to the gas hydrocarbons when they hit a surface which is lower than their boiling point?

Answer 17

Condensation

Question 18

Name the properties of long hydrocarbons

Answer 18

High boiling points, viscous, darker in colour, not very volatile

Question 19

Where do long hydrocarbons condense in a distillation collumn?

Answer 19

Lower down the column

Question 20

Learn the different fractions of the fractionating column

Answer 20

Question 21

What part of the fractioning column stop condensed hydrocarbons running back down the column and provides the surface for condensation?

Answer 21

Bubble Caps

Question 22

What is the range of carbons in the hydrocarbon chain found in the fractionating column?

Answer 22

~3 - 70+

Question 23

Name a use of the refinery gases

Answer 23

Bottled gas/heating

Question 24

Name a use for gasoline

Answer 24

Fuel for cars

Question 25

Name a use for Naphtha

Answer 25

Starting material for chemical production of paints, explosive etc.

Question 26

Name a use for kerosene(paraffin)

Answer 26

Jet engines, paint solvent

Question 27

Name a use for diesel

Answer 27

Fuel for diesel engines

Question 28

Name a use for fuel oil

Answer 28

Domestic central heating

Question 29

Name a use for bitumen

Answer 29

Road surfacing and asphalt for roofs

Question 30

What is cracking?

Answer 30

The process of breaking large hydrocarbons down into smipler molecules by heating them

Question 31

What are the properties of small hydrocarbons?

Answer 31

Low boiling points, very volatile (ignite easily), flows easily

Question 32

What are the products of cracking?

Answer 32

Smaller alkanes, and alkenes

Question 33

What conditions are needed for cracking?

Answer 33

600-700^oC, and an aluminium oxide (alumina) + silicon dioxide catalyst

Question 34

What is the difference between the molecular and structural formula?

Answer 34

Molecular formula: Type and number of atoms in the molecule Structural formula: Arragements of the atoms within the molecules

Question 35

What is an isomer?

Answer 35

Compounds with the same molecular formulae but different structural formulae

Question 36

Give an example of cracking

Answer 36

Dodecane --\> Octane + Ethene C₁₂H₂₆ --\> C₈H₁₈ + 2C₂H₄

Question 37

What happens to the boiling point of isomers when branching occurs?

Answer 37

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Question 38

What process turns vegetable oil into olive spread?

Answer 38

Hydrogenation

Question 39

What does the process of hydrogenation entail?

Answer 39

Turning the liquid vegetable oil into solid spread (Unsaturated fatty acids to saturated fats)

Question 40

What type of cumbustion occurs when there is plenty of oxygen?

Answer 40

Complete combustion Alkane + Oxygen --\> Cardon Dioxide + Water

Question 41

What reaction occurs when there is not enough oxygen for combustion?

Answer 41

Incomplete combustion alkane + oxygen --\> carbon + carbon monoxide + water

Question 42

What is required to make an alkane react with halogens?

Answer 42

UV light