C1 -Carbon Chemistry

Fossil fuels = finite resources, eg. coal and oil. They are being used up faster than they are made, so are non-renewable.

Crude oil = a mixture of different types of hydrocarbons (made only of carbon and hydrogen atoms). These different oils can be separated through fractional distillation. Bitumen has a very high boiling point, so does not boil and exits the fractionating column at the bottom as a liquid. The gases of the other hydrocarbons rise and fractions with lower boiling points exit towards the top of the colomn, eg. LPG and Petrol.

Extracting oil can be problematic:

- chances of oil slicks which damage birds feathers and cause them to die

- politically unstable countries can drastically alter the price of oil for non-oil producing countries

- there are conflicts about use of the crude oil (petrochemicals vs. fuels)

Cracking is the process which turns large alkane molecules into smaller alkanes and alkenes, helping oil manufacturers math demand for certain types of products.

Burning fossil fuels results in the releasing of carbon dioxide which can be damaging to the environment. Countries with huge populations such as China and India use more fuel, so release more carbon dioxide. 

Complete combustion takes place when there is surplus oxygen, producing plenty of energy.

Methane + Oxygen -> Carbon Dioxide + Water

Incomplete combustion happens when there isn't enough oxygen for the fuel to burn properly. It causes soot and carbon monoxide to be made instead of carbon dioxide which can be harmful.

Methane + Oxygen -> Carbon Monoxide + Water

or

Methane + Oxygen -> Carbon + Water

Clear air is made of 78% nitrogen, 21% oxygen and the remaining 1% is made up of other gases such as carbon dioxide. These figures do not alter much as there are processes which balance the production and useage of carbon dioxide and oxygen. As a result of things such as deforestation and population increase this balance is disturbed which causes the levels of carbon dioxide in the air to change. 

One theory about the Earth's original gas make-up is that the atmosphere was rich in both carbon dioxide and water vapour, but the water vapour condensed to form oceans and the carbon dioxide was absorbed. As nitrogen isn't very reactive, little was removed from the atmosphere so it became the most prominant gas. Plants photosynthesised, resulting in more oxygen than carbon dioxide in the atmosphere, giving us our atmospheric make-up today.

Pollution control is important and things such as catalytic converters can be used to reduce the levels of nitrous oxides and carbon monoxide in the atmosphere, using a catalyst.

2CO + 2NO -> N₂ + 2CO₂

Alkanes = saturated hydrocarbons with only single covalent bonds.

Alkenes = unsaturated hyrdocarbons with a double covalent bond between two carbon atoms. When bromine water is added to an alkene it decolourises and forms a dibromo compound, in an addition reaction.

Addition polymerisation = when alkene monomers are reacted under high pressure with a catalyst to form a chain (polymer).

During an addition polymerisation reaction the double bond is broken and the two carbon atoms form new bonds, allowing multiple monomers to become attatched.

In this reaction, multiple unsaturated monomers are joind together to make one saturated polymer.

GORE-TEX is a material which has all the properties of nylon (tough, lightweight, water resistant) but is also breathable, meaning it lets sweat out. It is made from the designer polymer PTFE.

PTFE contains tiny holes which allow water vapour to exit, but are too small for large water molecules to enter, so it is water resistant, but still breathable.

Atoms in polymers are held together through strong covalent bonds. 

Plastics with weak intermolecular forces between polymer molecules have low melting points. They stretch easily because they slide over eachother

Plastics with strong cross-links have high melting points and are rigid because the atoms are secured in place.

When proteins, such as eggs, are cooked the protein molecules denature, permanently changing shape.

Carbohydrates, such as potatoes,are easier to digest when cooked. This is because the starch grains swell, rupturing the cell walls. As a result their structure changes and they gain a softer texture. 

Baking powder is sodium hydrocarbonate and is used in cooking because it decomposes when heated.

Emulsifiers are used to bond oil/fat with water to stop them from seperating.

The molecules have hydrophillic heads (water loving) and hydrophobic tails (oil/fat loving) which bond to the water and oil molecules repspectively to stop them from separating. 

Esters are used to make perfumes.

Alcohol + Acid -> Ester + Water

Perfumes need to be non-toxic, evaporate easily, unreactive with skin/water, insoluble in water.

Volatiliy = ease of evaporation.

To evaporate liquid particles need sufficient kinetic energy to overcome the forces of attraction with other molecules in the liquid. Liquid perfume has only weak attractions so are easy to overcome and evaporate easily.

Nail varnish cannot be dissolved by water because the attraction between the water molecules is stronger than between the water and nail varnish.

Paint is a colloid with the particles small and dispersed so they don't settle.

Paints dry when the solvent evaporates.

In oil paint the solvent evaporates and the oil is oxidised forming a protective skin.

Emulsion paints dry when the water evaporates, with the oil droplets spreading out to form a protective film.

Thermochromic pigments change colour at different temperatures.

They can be added to acrylic paints to create more colour changes.

Phosporescent pigment glows in the dark.

They absorb and store energy and release it as light over a period of time.