Organic Chemistry

Question 1

What is crude oil made out of?

Answer 1

Hydrocarbons.

Question 2

What are hydrocarbons?

Answer 2

Compounds that are made of only carbon and hydrogen.

Question 3

What is the formula for an Alkane?

Answer 3

Cn H2n+2

Question 4

What is the formula for an Alkene?

Answer 4

Cn H2n

Question 5

What is the formula for an Alcohol?

Answer 5

Cn H2n+1 OH

Question 6

What is the formula for a Carboxylic Acid?

Answer 6

Cn H2n+1 COOH

Question 7

What is viscosity?

Answer 7

How thick a fluid/substance is.

Question 8

What factors increase or decrease as you go up a fractional distillation column?

Answer 8

• The hydrocarbon chain length decreases (gets shorter)
• The boiling points decrease
• The ease of ignition increases
• Viscosity decreases (become less thick)

Question 9

What is the purpose behind fractional distillation?

Answer 9

It separates crude oil (which is a mixture of lots of different hydrocarbons) into smaller and more useful mixtures.

Question 10

How can you identify an alkane through its properties?

Answer 10

• The suffix of its name is ‘ane’
• It contains a single bond between the carbons
• The formula (Cn H2n+2)

Question 11

How can you test for an alkane?

Answer 11

Place the substance in bromine water.

The bromine water will stay orange/brown (experience no colour change) because alkanes are saturated.

Question 12

How can you identify an alkene through its properties?

Answer 12

• The suffix of its name is ‘ene’
• It contains a double bond
• The formula (Cn H2n)

Question 13

How can you test for an alkene?

Answer 13

Place the substance in bromine water.

The bromine water will turn colourless because alkenes are unsaturated.

Question 14

How can you identify alcohol through its properties?

Answer 14

• The suffix of its name is ‘anol’
• It contains an OH (hydroxide) group
• The formula (Cn H2n+1 OH)

Question 15

How can you test for alcohol?

Answer 15

Alcohols combust very well:

- They react with oxygen to make carbon dioxide and water

Question 16

How can you identify a carboxylic acid through its properties?

Answer 16

• The suffix of its name is ‘anoic’
• It contains a COOH (carboxyl) group
• The formula (Cn H2n+1 COOH)

Question 17

How can you test for a carboxylic acid?

Answer 17

• React with carbonate to produce salt, water, and carbon dioxide.
• React with magnesium (and other reactive metals) to produce a salt and hydrogen
• Universal Indicator will turn red - yellow because it is an acid.

Question 18

What is the equation for complete combustion?

Answer 18

Fuel + Oxygen –> Carbon Dioxide + Water

Question 19

What is the equation for incomplete combustion?

Answer 19

Fuel + Oxygen –> Carbon + Carbon Manoxide + Water

Question 20

How does incomplete combustion occur?

Answer 20

When the oxygen supply is limited.

Question 21

What are the health hazards of incomplete combustion?

Answer 21

Carbon monoxide is toxic: It binds to haemoglobin in red blood cells, preventing oxygen from binding, suffocating our cells and ourselves.
Soot is dangerous to breathe in: Soot is tiny carbon particles. This is harmful to breathe in and causes respiratory problems, which are worse for asthmatic people.

Question 22

What is the equation for hydrogen combustion?

Answer 22

Hydrogen + Oxygen = Water (vapour)

Question 23

What are the benefits of using hydrogen as a fuel?

Answer 23

• Burns easily
• Does not produce ash or smoke (produces water vapour)
• Releases nearly 3 times as much energy per kg as petrol.

Question 24

What are the disadvantages of using hydrogen as a fuel?

Answer 24

• Is a gas, so it has to be stored at high pressures.

- Filling stations around the world would have to be adapted for hydrogen cars.

Question 25

How can hydrogen be produced in a car?

Answer 25

Electrolysis of water.

Question 26

What is cracking?

Answer 26

The process where we break down long hydrocarbons into smaller and more useful hydrocarbons.

Question 27

What are the 2 methods of cracking?

Answer 27

- Catalytic cracking | - Steam cracking

Question 28

How does catalytic cracking work?

Answer 28

- Uses a temperature of about 550°C | - Use of a catalyst; for example, a porous pot catalyst

Question 29

Why do we crack hydrocarbons?

Answer 29

There is a higher demand than supply of shorter hydrocarbons, so we crack longer chains.

Question 30

What is a polymer (addition polymer)?

Answer 30

A substance that is made up of small repeating units (alkenes).

Question 31

For example, what is Poly(ethene) made of?

Answer 31

A combination of many ethene molecules (monomers).

Question 32

What does a repeating unit look like?

Answer 32

``` [ H H ] [ ¦ ¦ ] -[- C -- C -]- [ ¦ ¦ ] [ H H ] ```

Question 33

What are condensation polymers?

Answer 33

Polyesters that form an ester link.

Question 34

What two monomers do polyesters need?

Answer 34

- A molecule containing two carboxylic acid groups (COOH) | - A molecule containing two alcohol groups (OH)

Question 35

How does condensation polymerisation work?

Answer 35

- Two different monomers react together to form a water molecule - The other molecule has a carboxylic acid group and an alcohol group - These groups can react with more monomers, which forms a long polyester molecule.

Question 36

Give examples of biological polymers.

Answer 36

- DNA (nucleotides) - Proteins (amino acids) - Starch (sugar/glucose)

Question 37

What are the disadvantages of manufacturing polymers?

Answer 37

- Crude oil is a finite resource - It is non-renewable - Often imported (costs and supply vary)

Question 38

What does 'biodegradable' mean?

Answer 38

A material that will eventually rot away because microbes feed on them.

Question 39

What are the disadvantages of disposing of polymers?

Answer 39

- Landfill sites (running out of the land, not biodegradable, lasts for years) - Burning (releases toxic gases when they burn)

Question 40

What are the advantages of disposing of polymers?

Answer 40

- Recycling (can be melted and moulded into new objects) | - Biodegradable polymers are being developed.

Question 41

What are nanoparticles?

Answer 41

A substance that contains only a few hundred atoms.

Question 42

What are nanoparticles useful for?

Answer 42

- sunscreens (absorb harmful UV light from the sun) - lightweight strong materials (carbon nanotubes) - future drug delivery systems (buckyballs - hollow balls of carbon atoms)

Question 43

What are the hazards associated with nanoparticles?

Answer 43

- Can be breathed in, absorbed through the skin or transported into cells. - They take a long time to break down - They attract toxic substances to their surfaces

Question 44

What is the equation for surface area: volume ratio?

Answer 44

total surface area s.f : v ratio = -------------------------------- volume