crude oil

crude oil

1. Synthetic and natural materials

   • The materials we use are chemicals or mixtures of chemicals. For example, sugar is a chemical, but chocolate is a mixture of chemicals , one sugar
   • Materials can be obtained or made from living things. Examples include cotton, paper, silk and wool. These are sometimes called natural materials.
   • Materials can also be made from chemicals.Examples of these are plastics such as polythene used in shopping bags. These are called syntheetic material

2. Refining crude oil

   • rude oil is a raw material obtained from the Earth’s crust. It is a mixture of many different chemicals, most of which are hydrocarbons.
   • Crude oil is not very useful until it has been processed at an oil refinery.
     • The process of refining involves separating the hydrocarbons into fractions or batches using a technique called fractional distillation
       • Each fraction separates as they have different boiling points. The crude oil is heated in a furnace to around 400°C.
         • his allows all of the hydrocarbons in the crude oil to move into the bottom of the fractionating tower. The tower is hottest at the bottom and coolest
   • Size and properties of molecules
     • The size of a molecule has an effect on the properties that molecule shows. For example, the boiling point of hydrocarbons increases as the number of
       • carbon atoms in the molecule increases
       • This is because forces between molecules increase as the size of the molecule increases.
         • Hydrocarbons with up to four carbon atoms are gases, five to 16 carbon atoms are liquids and hydrocarbons with more than 16 carbon atoms are solids.

3. Polymerisation

   • Some small molecules (monomers) can join together to make very long molecules called polymers. This process is called polymerisation.
   • Many polymers are made from chemicals that are obtained from crude oil. For example, molecules of ethene join together to make poly(ethene),
   • By polymerising other small molecules, a wide variety of different polymers can be made. These synthetic materials have many uses.

4. Rearrangement of atoms

   • in a chemical reaction, the substances that react together are called the reactants, while the substances that are formed are called the products.
   • As a chemical reaction takes place, atoms in the reactants are rearranged to make the products.
     • The number of atoms of each element in the reactants is the same in the products
       • No atoms are added or taken away. This is called the conservation of atoms.

5. New synthetic materials

   • New synthetic materials are often used to make items that at one time were made from natural materials. The new material often has better properties,
   • Window frames used to be made from wood. This has to be painted regularly, and in time may rot. new window frames are made from uPVC, a syntheticpolym
     • The ‘u’ means it is unplasticised so is different from regular PVC. This can be made in a variety of colours, never needs to be painted, does not rot