Organic Chemistry

Question 1

What is a hydrocarbon

Answer 1

Any compound made of only hydrogen and carbon

Question 2

What is a functional group?

Answer 2

Atoms or groups of atoms in a molecule that determine chemical properties of a compound

Question 3

What is a saturated compound

Answer 3

A hydrocarbon with no double bonds (alkanes)

Question 4

What is an unsaturated compound?

Answer 4

A hydrocarbon with one or more double bond

Question 5

What is the general formula for alkanes

Answer 5

C(n)H(2n)+2

Question 6

What is the general formula for alkenes?

Answer 6

C(n)H(2n)

Question 7

What are the first five alkanes

Answer 7

Methane, ethane, propane, butane, pentain

Question 8

What are the first 5 alkenes

Answer 8

Ethane, propane, butane, pentane, hexane

Question 9

Why does the boiling point of alkanes increase with chain length?

Answer 9

• more atoms and bonds on one line need a larger force to separate

Question 10

Why are short chain hydrocarbons more volatile ?

Answer 10

• have a lower boiling point so they evaporate easier

Question 11

What is more flammable , short chain or long chain hydrocarbons?

Answer 11

Short chain alkanes

Question 12

What is meant by refined

Answer 12

Separated

Question 13

How is crude oil formed

Answer 13

Plankton is compressed by heart and pressure typically by the ocean and over a long time produces crude oil

Question 14

What is meant by oxidisation?

Answer 14

When oxygen bonds to a hydrocarbon to make H2O

Question 15

What is combustion

Answer 15

Burning (rapid reaction between a substance and oxygen

Question 16

What is the difference between complete and incomplete combustion?

Answer 16

In incomplete combustion there is not enough oxygen to create carbon dioxide, so carbon monoxide is produced instead

Question 17

What is the equation for combustion?

Answer 17

Hydrocarbon fuel + oxygen = carbon dioxide + water

Question 18

What are the properties of complete combustion?

Answer 18

• blue flame
• little / no soot

Question 19

What are the properties of incomplete combustion?

Answer 19

• yellow flame
  -soot (carbon)

Question 20

What are the properties of carbon monoxide?

Answer 20

• colourless
• odourless
• very toxic (staves body of oxygen as CO binds better to hoemoglobin than oxygen so starves blood of oxygen

Question 21

What are the problems with particulates (soot)

Answer 21

• creates smog - dark clouds cause global dimming
• respiratory problems caused when inhaled

Question 22

What is meant by airpollution

Answer 22

Products of incomplete combustion

Question 23

What are the problems with nitrogen oxide and sulfur dioxide?

Answer 23

• damages lungs if inhaled
• gets in clouds and forms dilute acids (acid rain)

Question 24

What are the problems with acid rain?

Answer 24

• damages buildings
• corrodes metals
• damages plants
• makes soil acidic

Question 25

What are the early atmospheric gases?

Answer 25

- carbon dioxide, - water vapour - methane - ammonia (NH3)

Question 26

What are the proportions of the earths atmosphere today?

Answer 26

- nitrogen 78% - oxygen 21% - argon 0.9% - carbon dioxide 0.037%

Question 27

How was the early atmosphere formed?

Answer 27

- volcanoes dispersed volatile chemicals that made up the atmosphere - CO2 kept earth hot - volcanoes release co2 and h2o - H2O condensed to form seas - co2 dissolved in seas and became locked up in rocks - photosynthesis by primative plants produced oxygen - levels of co2 decreased, levels of oxygen increased

Question 28

What is the greenhouse effect?

Answer 28

- Sun rays go through the earths atmosphere - reflect of the earth - rebound into the atmosphere to keep the earth warm like a greenhouse

Question 29

What method can be used to see how much CO2 levels change over time

Answer 29

Ice cores- counting bubbles and measuring them for CO2

Question 30

What creates methane?

Answer 30

- agriculture - decomposition of rubbish in landfill

Question 31

What creates CO2?

Answer 31

- fossil fuels - deforestation

Question 32

What are the effects of climate change?

Answer 32

- polar ice caps melt ( causing rising sea levels) - extinction of species living in cold climates as temp getting too hot - change in rainfall (droughts and flood) - change in species distribution

Question 33

What do the names of alkanes end in?

Answer 33

- ane

Question 34

What do the names of alkenes end in?

Answer 34

-ene

Question 35

What are the solutions to lowering methane and co2 emissions?

Answer 35

- carbon capture and storage (co2 absorbed into porous rocks like limestone) - eat less meat (fields for animals can be used for plants)

Question 36

What are the two impurities of hydrocarbons?

Answer 36

- nitrogen oxide, sulphur dioxide

Question 37

What is meant by ‘locked up’?

Answer 37

CO2 becomes a carbon compound in plants and decomposed into fossil fuels and sedimentary rocks

Question 38

What are examples of renewable energy sources

Answer 38

- wind - soar - nuclear

Question 39

How can manufacturing processes be more efficient

Answer 39

Use less energy, produce less waste

Question 40

How can you calculate carbon footprint?

Answer 40

Take into account: - how raw materials are sourced - manufacturing process - transportation - total amount of power used in its lifetime - how disposed of

Question 41

What is a carbon footprint?

Answer 41

The total amount of CO2 and greenhouse gases emitted over something’s lifetime

Question 42

What are the benefits of a carbon footprint?

Answer 42

- determines how eco damaging a product is (is it worth it) - identify the most polluting activities

Question 43

What is thermal decomposition?

Answer 43

A reaction when a compound is broken down into a simpler substance when heated

Question 44

What is the equation for thermal decomposition with calcium carbonate

Answer 44

CaCO3=CaO+CO2

Question 45

What is cracking?

Answer 45

Breaking down long chain hydrocarbons into short chain hydrocarbons by thermal decompositon

Question 46

Why do we crack long chain hydrocarbons?

Answer 46

Highest demand is for short chain hydrocarbons

Question 47

What are the problems with long chain hydrocarbons

Answer 47

- difficult to ignite - burns incompletely (produces soot)

Question 48

What are the two methods of cracking?

Answer 48

Steam cracking and catalytic cracking

Question 49

What is the process of catalytic cracking?

Answer 49

- hot (500’c) powdered aluminium oxide (catylist) - pass vapourised long chain hydrocarbon over powder - eventually long chain splits

Question 50

What is the process of steam cracking?

Answer 50

- mix vapourised long chain hydrocarbon with steam - heat to a very high temperature (450-700)

Question 51

What are polymers

Answer 51

Long chain molecules made from short chain monomers

Question 52

Why do polymers have high melting points even though they have covalent bonds?

Answer 52

They are simple molecular substances

Question 53

What are the order of fractions in fractional distilition (top to bottom_)

Answer 53

- refinery gases - petrol - naphtha - kerosine - diesel - lubricating oil - fuel oil - bitumen residue