Chemistry Unit 1 OCR Gateway Revision Cards

• crude oil is a thick, viscous mixture of substances

• crude oil is mainly a mixture of hydrocarbons, a compound of hydrogen and carbon atoms ONLY.

• eastern countries, e.g Saudi Arabia
• tremendous political power
• political conflicts (over whether or not they share)
• shortages of the fuel, making it more expensive
• relying on politically unstable countries, meaning that we could be cut off at any time

• families or homologous series of hydrocarbons, the simplest being alkanes.
• they are a saturated molecule, and their formula is:
• CxH2x+2
• they look like this:
• e.g. ethane.

• isomers are different structural formulas of the same compound, so they have the same molecular formula.

• by their melting or boiling points
• this is used when refining crude oil

• 'the higher the number of carbon atoms in a molecule, the higher the boiling point.'

• crude oil is a fairly useless mixture of hydrocarbons, which can be seperated into useful fractions. because different hydrocarbons have different boiling points, if the crudeo oil is heated, differnt fractions can be collected at different temperatures.

• similar molecular weights with a similar range of boiling points

• a fractionating column
• crude oil is pumped in as vapour at the hottest part (the bottom) and condenses at a  different temperature, and is collected.

• the more viscous it is
• the darker the colour
• th harder it is to ignite it
• the smokier the flame

• Cracking.

• high temp
• catalyst

• decane-

• dodecane-

• Toxicity - how poisonous is it?
• Energy value - energy/kg fuel?
• Availability -transportation, easy?
• Cost - how expensive?
• Usability - ease of use?
• Pollution -production of pollutants
• Storage - easy/safe to store?

• fuel oil
• petrol
• paraffin wax
• LPG
• bitumen

• Bromine water
• it decolourises when coming into contact with an unsaturated,
• e.g. ethane

• e.g. ethene 

• alkenes
• e.g. ethene

• an unsaturated hydrocarbon means that it contains one or more carbon to carbon double bond.

• population is wealthier and more materialistic
• bigger population - always increasing
• fossil fuels are burned to make steam to power the turbine, which makes electricity
• we are tending towards being a thrown away society.

• when any substance burnes it combines with oxygen to form an oxide
• all fuels are hydrocarbons
• the hydrogen burns to give hydrogen oxide
• the carbon burns to give carbon dioxide

• carbon dioxide and water vapour are formed

plenty of air in as airhole open -plenty of oxygen so complete combustion

clean flame

hotter flame

burns faster with more pressure

tip of cone is hottest part

• shortage of air in, as airhoel closed - not enough oxygen so produces CO2 and CO
• yellow from illuminated carbon particles
• cooler flame with less pressure

• poisonous restricts O2 intake in the blood
• colourless
• no smell
• invisible, you cannot detect it until the symptoms show
• it kills you

• If a fuel burns in a shortage of oxygen it gives off unwanted gases, these gases contain soot and are toxic.
• one of the toxic fumes is a gas called carbon monoxide
• carbon monoxide is a poisonous gas and is very dangerous if it is breathed in
• sometimes a heater in a poorly ventilated room in a house becomes faulty and burns fuel in a shortage of oxygen. This causes it to give off carbn monoide and the people who live in the house are in danger of being made ill or even dying from carbon monoxide poisoning.
• heaters should be checked regularly to make sure it is burning properly.

• deforestation
• burning fossil fuels
• using ossil fuels to make electricity

• it is created by burning fossil fuels
• it dissolves with water to make dilute sulphuric acid
• which is aa kind of acid rain

• it is formed by internal heat combustion engines
• dissolves into water to form nitric acid
• acid rain

• photochemical smog are bad atmospheric pollutants that can be damaging to our health. This smog is formed when nitrous oxide rects with other pollyutions, especially in things like sunlight.

• acid rain is a rain that's acids are very dilute. usually made up of nitrogen oxide and sulphur dioxide, and this can be harmdul because it is corrosive and can wear down forests by killing trees, and sometimes animals.  It can also corrode metal and stone.

• thermoplastic polymers have intermolecular forces between the polymer chains are fairly weak so these polymers are fairly weak so these polymers have low melting points are are stretchy, because the chains can slip over eachother (they can usually be remolded)

• these polymers have cross linking bridges which means they have high melting points and are rigis and cannot be stretches. they are usually used in appliances which have to withstand heat.

• firstly, HDPE has a much higher boiling point than LDPE, measuring 120degC, whereas the boiling point of LDPE is 85degC
• HDPE is more rigid and hard than LDPE
• HDPE is 3 times stronger in MPa
• HDPE is slightly higher in density (g/cm3)

• waterproof clothing, especially nylon coated, stops any water vapour coming through the fabric, but also does not let any sweat vapour out, making you feel hot and clammy. Breathable clothing stops the water getting in, but also lets the sweat get out also. This is because breathable clothing such as gore-tex consists of many layers, and the holes in these layers are too small to let water vapour through, but are still big enough so that the smaller sweat vapour particles can pass through.

• strong and rigid polymers such as HDPE are used to make plastic ilk bottles
• lght stretchable polymers much as LDPE are used for plastic bags and queezy bottles.
• PVC is strong and durable, it can be made either rigid or stretchy.
• Plystyrene foam is used in packaging to protect brekable things and it is used to make disposable coffee cups.

• they are unreactive, so they are biodegradable - disposal is a problem
• they use landfill to dump the rubbish but they are filling up
• they burn them but that produces carbon dioxide and toxic gases

• to kill microbes
• makes it taste better, more flavorous
• to improve texture
• to make it digestible

• meat
• fish
• eggs

(all protein)

• they DENATURE.
• they can never return to how they were.
• the change is PERMANENT.

• potatoes become more digestivle because the cell walls rupture when they are cooked, giving a softer texture, and the starch grains swell up and spread out.

• 2 NaHCO3 (s)-------> Na2CO3 (s) + H2O (l) + CO2 (g)
• it is used as a raising agent in cakes because it produces carbon dioxide which expands after being produced and is heated, which makes the cakes light and spongey.

• esthers
• esthers are mde from the reaction between alcoholic and carboxylic acid(alkanoic acid)