Crude oil is found in rocks and is used to produce fuels and other important chemicals.

Crude oil is a mixture of different compounds that are chemically bonded together with most compounds forming hydrocarbons.

Crude oil was made from the fossileised remains of ancient plankton.

A hydrocarbon is a carbon is a mixture soaly made form hydrogen and carbon.

Fractional distillation is the process of separating crude oil into groups of hydrocarbons similar numbers of carbon atoms.

Short chain hydrocarbons are hydrocarbons with few carbon atoms and long chains are the opposite.

1) A crude oil is a mixture made from different hydrocarbons with each having different boiling points. Longer chained hydrocarbons have higher boiling points.

2) The crude oil is heated in the fractionating Colum and the oil evaporates and condenses at a range of different temperatures.

3) The fractioning Colum works by piping in heated crude oil at the bottom. The vaporized oil rises up the Colum and the virus temperature where it is constantly tapped off where they condense.

4) The fractions can be used as fuels or feedstock in the petrochemical industry.

The members of this series have similar properties yet physically , it can change.

Some properties of hydrocarbons depend on the size of the molecules. These properties influence their use as fuels.

Shorter chained molecules are less viscus and longer chained molecules are more viscus. Viscosity is a measurement of how runny it is.

The shorter the molecules , the lower the temperature at which it condenses and evaporates. Hence , shorter chained molecules are found at the top of the Colum.

The shorter chained molecules are more flammable.

Whenever a hydrocarbon reacts , it always depends on the amount of oxygen available.

2) Incomplete combustion produces carbon monoxide and soot

1) Incomplete combustion occurs when there is not enough oxygen. This is a partial combustion.

3) carbon monoxide is a colorless , odorless gas that is toxic. if breathed , it attaches to the red blood cells and which can lead to death.

4) Soot can often cause dimming and be an irritant.

1) Sometimes , impurities like Sulphur or nitrogen can react in a the burning of fossil fuels.

2) Sulphur oxides when burned produce oxide Sulphur dioxide. When inhaled , Sulphur can cause respiratory problems.

3) Sulphur oxide when it reacts with water vapor in the atmosphere can also create acid rain. Acid rain is the cause to steel corrosion , the weathering of buildings and streets and the death of wildlife.

1) Nitrogen in the internal combustion of engines can also be formed. it is also toxic when reacted with oxygen to form nitrous oxide.

Hydrogen fuel cells can be use as alternatives to petrol fuels.

1) Hydrogen fuels only make water as a by product and means that no gasses are emitted into the atmosphere.

They have a high capacity and produce more energy per gram.

They can often be hard to store as they have to be pressurized and they are not many places to refill.

1) Hydrocarbons can be cracked to make smaller and more useful molecules.

2) They are usually vapors that have been passed over a hot catalyst or mixed with steam at a high temperature for thermal decomposition to occur.

3) The demand for short chained hydrocarbons is much greater as they can ignite easily and are more useful as fuels.

1) In the past , intense volcanic activity meant that carbon dioxide was constantly being released into the atmosphere. This made that atmosphere more akin to Venus or mars. Over time , the nitrogen amount as well as the carbon dioxide particles as well as other chemicals. Also increased. The formation of oceans reduced the amount of carbon dioxide in the atmosphere and carbonate particles were produced as a result.

2) Photosynthesis is used by many plants and it increases the amount of atmospheric oxygen. photosynthesis is the process where light is used to convert carbon dioxide into glucose and oxygen.

3) Algae and other marine microorganisms were the first to ever undergo the process of photosynthesis around 2,7 million years ago. Subsequently , the amount of co2 decreased.

1) use a glowing splint and insert it into a test tube. If it reignites , oxygen is present.

An exothermic reaction is a reaction that transfers energy to the surrounding and the energy in making bonds is greater than breaking bonds.

Some examples of exothermic reactions are: respiration , oxidation , neutralization , and the dissolving of a salt in an aqueous solution.

An endothermic reaction takes the energy from the surrounding and the energy in breaking the bonds is greater than making the bonds.

Some examples are the thermal decomposition , the reaction between citric acid and hydrogen carbonate and a sports pack.

Particle theory states for chemicals reactions to occur , they must collide with enough energy known as the activation energy.

In order to increase the rate of reactions , you need to increase the frequency so that more of them have the activation energy.

Increasing the frequency of success full collisions is dependent on pressure , concentration , surface and the use of a catalyst.

Group 7 is consists of fluorine , chlorine , bromine , iodine and astatine.

Chlorine is a yellow-green gas , bromine a red-brown liquid and iodine a purple solid.

The further down you go on group 7 , the more solid they become. This is becasue