Organic Chemistry

Question 1

What are the properties of the homologous series?

Answer 1

• family of compound with similar chemical properties
• represented by a general formula
• show a gradual trend in physical properties e.g melting and boiling points
• always a diff of CH2 between one member and the next in the series

Question 2

two examples of homologous series are:

Answer 2

• The alkanes

- The alkenes

Question 3

What are all molecules in the alkanes and the alkenes?

Answer 3

Hydrocarbons

Question 4

What are hydro carbons?

Answer 4

compound made of only hydrogen and carbon

Question 5

What are the alkanes in terms of hydrocarbons

Answer 5

Saturated

Question 6

definition of saturated?

Answer 6

Atoms are joined together by single covalent bonds

Question 7

the aliens are what kind of hydrocarbon?

Answer 7

unsaturated

Question 8

definition of unsaturated?

Answer 8

Chemical compounds that contain carbon-carbon double bonds.

Question 9

When naming an alkane what must one remember?

Answer 9

-All alkanes end with the suffix -ANE
- the number of carbon atoms in the molecule is represented by a specific prefix
E.G. Methane, ETHane, PROPane, BUTane,PENTane, HEXane

Question 10

What is the general formula for Alkanes?

Answer 10

CnH2n+2

^ the n represents the number of carbon atoms

Question 11

What must one remember when naming an alkene?

Answer 11

• All alkenes end with the suffix -ENE

- By the number of C atoms in the molecule is represented by the same prefix as for the alkanes.

Question 12

What is the general formula for Alkenes?

Answer 12

CnH2n

Question 13

definition of an Isomer? (Do not confuse with isotope)

Answer 13

Isomers are molecules with the SAME MOLECULAR FORMULA BUT A DIFFERENT STRUCTURAL FORMULA.

Question 14

Alkanes are unreactive molecules what does this mean?

Answer 14

they do not burn in air to produce carbon dioxide ad water and release energy

Question 15

when do alkanes react with bromine?

Answer 15

in the pre scene of UV light

Question 16

what is the word equation for the bromine and methane reaction? and what kind of reaction is it?

Answer 16

Methane+ Bromine= Bromoethane + hydrogen bromide.

-substitution reaction

Question 17

why are alkenes reactive molecules?

Answer 17

Because they have a carbon carbon double bond

Question 18

Why are alkenes not used as fuels?

Answer 18

They are to valuable

-used to make plastics

Question 19

What do alkenes react with bromine to make a reaction occur?

Answer 19

React with bromine or bromine water and do not need uv light for this reaction to occur.

Question 20

what kind of reaction is Alkene and bromine?

Answer 20

Addition reaction

Question 21

What colour is bromine?

Answer 21

orange/brown

Question 22

What is crude oil?

Answer 22

-it is a fossil fuel

a mixture of hydrocarbons of different sized

Question 23

What is the process of distillation of crude oil?

Answer 23

• Crude oil is heated so it becomes a mixture of vapours.
• vapour pass in fractoining column where they cool.
• the different fractions cool at different temps because …
• defferent hydrocarbons have different sized molecules so diff boiling/condensing point.

Question 24

what properties do the crude oil vapours at the top of the fractioning column have?

Answer 24

• low temperature (70C)
• small molecules condense
• light in colour
• runny (less viscous)
• very flammable
  e. g. petroleum gases, petrol, kerosine

Question 25

What properties do the crude oil vapours at the bottom of the fractioning column have?

Answer 25

- high temperatures (360C) - large molecules condense - dark in colour - think and viscous - difficult to light

Question 26

Definition of boiling point?

Answer 26

the temperature at which the liquid boils or the gas condenses

Question 27

definition of volatility?

Answer 27

The tendency to turn into a gas

Question 28

definition of viscosity?

Answer 28

how easy it flows

Question 29

Definition of flammability?

Answer 29

how easily it burns

Question 30

what is the test for carbon dioxide?

Answer 30

turns limewater cloudy

Question 31

what is the chemical test for water?

Answer 31

anhydrous colbot chloride paper turns from blue to pink

Question 32

Physical test for water?

Answer 32

boils at 100C and freezes at 0

Question 33

When does complete combustion occur?

Answer 33

When there is plentiful/sufficient supply of oxygen

Question 34

When does Incomplete combustion happen?

Answer 34

if there is a limited/ insufficient supply of oxygen

Question 35

what is a dangerous product of incomplete combustion?

Answer 35

Carbon monoxide

Question 36

What is carbon monoxide?

Answer 36

a poisonous, colourless, tasteless, odourless gas.

Question 37

why is carbon monoxide dangerous? (cause and effect)

Answer 37

- binds more easily to haemoglobin in the blood than oxygen - carries around the body and reduced respiration - leads to unconsciousness or even death

Question 38

What is fermentation?

Answer 38

Conversion of sugars to ethanol

Question 39

what conditions are needed for fermentation.

Answer 39

temp of about 35C- (above 40C the yeast would be denatured - anaerobic conditions - aqueous solution

Question 40

What is the word equation for fermentation?

Answer 40

Glucose>>>>>>>>>ethanol + carbon dioxide | ^^ yeast enzymes//35C

Question 41

name a country which uses fermentation and reasons for it?

Answer 41

Brazil- have resources e.g. sugar beat +sugar cane. | climate is right, land and it can be produced v cheaply