[Part 2]- C9- crude oil and hydrocarbons ⛽️

• fractional distillation, is a process by which components in a chemical mixture are separated into fractions [different parts], according to their different boiling points.

• crude oil is separated by fractional distillation. • in fractional distillation, crude oil is separated into fractions.

• a fraction, contains hydrocarbons with a similar number of carbon atoms • [and some fractions may be used as fuels]

• crude oil is vaporised, and turned into a gas by heating • and the hydrocarbon gases will enter the fractionating column, and then rise up the fractionating column • as hydrocarbon gases rise up the column, they will cool down and once they reach their boiling point in the fractionating column, they will condense • and the hydrocarbon fraction is then collected

• because very long chain hydrocarbons have very high boiling points, long chain hydrocarbons are removed from the bottom of the fractionating column [which is hot]

• ; as very short chain hydrocarbons have very low boiling points, they are removed from the top of the fractionating column. [which is cool] • this means, they don’t condense and are therefore removed as gases

• petrol and diesel is used to fuel cars • kerosene is used as jet fuel • ; heavy fuel oil is used to power ships, and liquified petroleum gas is used in camping stoves

• Fill in the gaps: some fractions are used as feedstock, for the petrochemical industry

• a feedstock, is a chemical that is used to make other chemicals

• solvents • lubricants • detergents • and, polymers

• alkanes, only have single covalent bonds between the carbon atoms

• cracking, is when a long chain hydrocarbon molecules such as alkanes, are broken down [cracked] to produce a shorter chain molecule

• in catalytic cracking, a high temperature and catalyst is used • this is done at an oil refinery, in steel vessels known as crackers. In the cracker, a heavy fraction distilled from crude oil is heated to vaporise the hydrocarbons, and is then passed over a hot catalyst at 500*c

• a catalyst, is a substance that increases [speeds up] the rate of chemical reactions; it remains chemically unchanged itself, at the end of the reaction.

• in steam cracking, high temperatures and steam is used

• an alkene, is a molecule with a double covalent bond between two carbon atoms, which is more reactive than an alkane

• alkenes, are used to make chemicals known as polymers • alkenes are used as a starting material for useful chemicals

• since alkenes are more reactive than alkanes, they can be used to test for alkenes

• alkenes are tested with [orange] bromine water and then shaked. • if the bromine water turns colourless, an alkene is present

• the products of cracking are useful because, there is a high demand for short chain molecules which can be used as fuel

• steam cracking is done at an oil refinery, in steel vessels known as crackers. • In the cracker, a heavy fraction distilled from crude oil is heated to vaporise the hydrocarbons • and the hydrocarbon vapour is mixed with steam, and heated to a very high temperature

• in catalytic cracking, a high temperature and catalyst is used • this is done at an oil refinery, in steel vessels known as crackers. • In the cracker, a heavy fraction distilled from crude oil is heated to vaporise the hydrocarbons, and is then passed over a hot catalyst at 500*c

• steam cracking is when hydrocarbons are cracked, and broken down into shorter hydrocarbon molecules by mixing them with steam and heating them to a high temperature