Chemistry Unit 1 - Organic Chemistry

Fossil fuels

Formed from remains of dead organic matter over millions of years at high Temp./Pressure

Ex. of Fossil Fuels

Coal (s) = dirtiest

Crude oil (l) = petroleum

Natural gas (g) = cleanest

Issues with Fossil fuels

Carbon Dioxide Emissions

Non-renewable

Alternatives to fossil fuels

Renewable energy: wind, solar, hydroelectric

Nuclear E (no Carbon dioxide emissions)

Complete Combustion

Fossil Fuel (Hydrocarbon) + O2 ➡ CO2 + H2O

Incomplete Combustion

Insufficient O2, produces toxic CO (Carbon Monoxide)

Crude Oil

Mixture of Hydrocarbons called alkanes

Can be separated through fractional distillation

Fractional Distillation

Separating mixtures according to boiling point

Fractional Distillation of Crude Oil

Oil is heated in a heater to 400 Celsius, becoming vapour, and then sent through a fractionating column (attached to thermometer), where substances with high boiling points settle in lower levels while substances with low boiling points settle higher before condensing into individual substances.

Small Molecules

Low boiling point

Very volatile

Flows easily

Ignites easily

Large molecules

High boiling point

Not very volatile

Does not flow easily

Does not ignite easily

volatile

Evaporates easily

viscous

Thick and sticky

Refining

Purification of substances through physical separation

Refinery gas

Non-condensable gases

Organic compound prefix for one

Mono-

Organic compound prefix for two

Eth-

Organic compound prefix for three

Prop-

Organic compound prefix for four

But-

What do organic compounds form when in groups?

Families

Functional Group

Group of atoms that gives a family its particular reactivity

Homologous series

Family of similar compounds with similar compounds with similar chemical properties

Carbon forms x bonds

4

Hydrogen forms x bonds

1

Alkanes

Hydrocarbons

Only SINGLE C-C bonds

Suffix -ane

Alkanes General Formula

Cn H(2n+2)

Alkenes

Hydrocarbons

Contain a DOUBLE C-C Bond

Suffix -ene

Alkenes General Formula

Cn H(2n)

Alcohols

Suffix -ol

Functional Group: OH

Has to be bonded to C

Alcohols General Formula

CnH(2n+1)OH

How do you differentiate between the same organic compound when the double bond/OH is placed differently?

Number the carbon an write the number of the carbon where the thing is located in between pre and suffix

Eg. Butene (double bond at start)

But-1-ene

Carboxylic Acids

Suffix -oic acid

Functional Group COOH

They are weak acids

General Formula for Carboxylic Acids

CnH(2n+1)COOH

Alkane Reactions

• saturated (can’t fit any more bonds around the C)

• This makes them quite unreactive

• They do burn (combustion), releasing E

Alkenes Reactions

• unsaturated (when double bond breaks, more atoms can be added)

• Undergo addition reactions with H2, Br2, Hydrogen Halides and H20

Alkane + H2

ethene (C2H4) + H2 ➡ ethane (C2H6)

Alkane + Bromine Water (Br2)

ethene (C2H4) + Br2 ➡ 1,2 - dibromoethane (C2H4Br2)

Alkene + Hydrogen Halide (H + Hydrogen)

ethene (C2H4) + HCl ➡ chloroethane (C2H5CL)

Alkene + H20 (g)/Steam

ethene (C2H4) + H2O (g) ➡ Ethanol (C2H5OH)

Alkenes Polymerisation

Making plastics using Alkenes

Where do Alkenes come from?

Crude oil (Fractional Distillation at 400C) ➡ Alkanes (Cracking at 800C w Catalyst) ➡ Alkenes

Cracking

The process of turning larger Alkenes (not so useful) into smaller, more useful Alkenes

Thermal Decomposition at High T using a Catalyst

Alcohols Reactions

Ethanol: burns well in O2, giving out high E

2 ways Ethanol can be formed

• adding steam (H20) to ethene (industrial ethanol for perfumes, deodorants, etc.)

• Fermentation of glucose (simple sugar found in fruit/grains)

  • C6H1206 (Glucose) ➡(yeast catalyst) = 2C2H5OH (Ethanol) 2CO2

  • Anaerobic fermentation (no O2)

Ethanol in O2

Ethanol burns well, giving out high E

C2H5OH (Ethanol) + 3O2 (Oxygen) ➡ 3H2O + 2CO2

Ethanol in Cars

Can be used as fuel due to combustion abilities

Bio-fuels (renewable E sources)

Brazil are global leaders (use bioethanol from sugarcane fermentation to fuel cars)

Pros: renewable, clean no CO2 emissions

Cons: lots of land required, deforestation

Crude Oil to Plastic

Crude Oil (thru Fractional Distillation) ➡Alkanes (thru Cracking)➡Alkenes (Polymerisation) ➡ Plastics

Polymerisation

Many small molecules (monomers) join to form long chains (polymers)

Monomer

Small Molecule (ex. ethene)

Polymer

Long chain of small molecules (Polyethene)

Natural Polymers

Proteins, Carbohydrates, Fats, DNA

Synthetic Polymers

Plastics

ex.

ethene (monomer) ➡ polyethylene (polymer)

Polyethene (PE)

made from ethene 

used in bags, bottles, cling film

Polypropene (PP)

made from propene

used in crates, ropes

Polyamide (PA)

made from amide

used in tights, clothes, fishing nets

Polystyrene (PS)

styrofoam

made from styrene

used for insulation and packaging

Polyvinyl Chloride (PVC)

made from vinyl chloride

used water pipes, vinyl discs

Plastic Pollution

Plastics are:

Non-biodegradable

Filling landfills

Collecting in rivers/oceans

Wildlife eating plastic

Types of Polymerisation

Addition

Condensation

Addition Polymerisation

-many monomers add up to form a polymer

-monomer is a small alkene (C=C)

-double bond breaks and opens up

Repeating Unit

A single unit that is part of the polymer chain after polymerisation

Condensation Polymerisation

two diff monomers join and form a polymer and a small molecule (ex. H2O or HCl)

Amide link

The same link that joins amino acids to make proteins