Atoms and atomic structure:
· protons are in order of increasing atomic number
· vertical columns (group): elements with similar properties
· horizontal (row) period: atomic number increases
· compounds= atoms joined to other atoms using chemical bonds
- chemical bonds=electrons from reacting atoms being transferred from one to another.
· mass of substance remains the same at the end of all reactions.
Fuels from crude oil:
· crude oil is a mixture of compounds called hydrocarbons.( compounds of only hydrogen and carbon)
· most crude oil hydrocarbons are alkanes
o alkane formulae= CnH2n+2
o for example (look at the pattern):
· Alkanes are saturated hydrocarbons.
· Distillation= a process that can be used to separate a pure liquid from a mixture of liquids. It works when liquids have varied boiling points.
· here is an example of a simple method, you will need to know this:
· 1) Ethanol heated and as it has a lower boiling point to water it evaporates.
· 2) Ethanol vapour is cooled and condenses.
· 3) Vapour condenses to form pure liquid. ect pure ethanol without impurities.
· Fractional distilation:
· Fraction distillation separates a mixture into a number of parts, called factions.
o Column- is hot at the bottom and cool at the top
§ substances with a high boiling point condense at the bottom, while substances with low boiling points condense at the top.
§ bellow is a image of fractional distillation of crude oil you will need to know this for your exam:
· Refinery gases:
o used for bottled gas
o used for fuel for cars
o used for making chemicals
o aircraft fuel
· Diesel oil:
o used for fuel for vehicles
· Fuel oil:
o used for:
o power station fuel
o ship fuel
o used for roads (tarmac)
In the fractionating column:
o at 25 degrees Celsius= gases escape
o at 200 degrees Celsius= liquids are removed
o at 350 degrees Celsius= solids are removed
When fuels burn they release gasses into the atmosphere such as:
o water vapour (hydrogen oxide)
o carbon dioxide
o carbon monoxide
o sulphur dioxide= causes acid rain which reacts with limestone and kills plants and fish in water
· Limestone= calcium carbonate, CaCo3
o when heated breaks down to form calcium oxide+ carbon dioxide
§ Calcium oxide is quick lime
§ yellow- hot
§ white- cold
§ quick lime reacts with water to form Calcium hydroxide which is slaked lime
§ makes lime mortar for building work
· limestone is used for:
o to neutralise access acidity in water/soil
o purify iron in blast…