Chemistry Unit 1 OCR Gateway Revision Cards

cards used for aiding this unit in revision


What is crude oil?

  • crude oil is a thick, viscous mixture of substances
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What is crude oil made up of?

  • crude oil is mainly a mixture of hydrocarbons, a compound of hydrogen and carbon atoms ONLY.
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Who has the oil, and what are the potential proble

  • 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
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What are ALKANES?

  • 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.
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What ia an isomer?

  • isomers are different structural formulas of the same compound, so they have the same molecular formula.
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How are substances (e.g. the alkanes) indentified

  • by their melting or boiling points
  • this is used when refining crude oil
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What is the relationship between the number of car

  • 'the higher the number of carbon atoms in a molecule, the higher the boiling point.'
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  • 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.
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finish the sentence.. each fraction contains hydro

  • similar molecular weights with a similar range of boiling points
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Describe what happens in fractional distillation.

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What is the name of the instrument used in fractio

  • 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.
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finish the sentence.. the higher the boiling point

  • the more viscous it is
  • the darker the colour
  • th harder it is to ignite it
  • the smokier the flame
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Supply and demand is unequal. What process helps t

  • Cracking.
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Describe the process of cracking.

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What are the conditions needed for cracking and ho

  • high temp
  • catalyst
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Give the cracking examples of -decane -dodecane

  • decane-
  • dodecane-
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What are the 7 things to take into consideration w

  • 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?
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Name the part of crude oil which is used for: cent

  • fuel oil
  • petrol
  • paraffin wax
  • LPG
  • bitumen
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What is the test for saturation/unsaturation?

  • Bromine water
  • it decolourises when coming into contact with an unsaturated,
  • e.g. ethane
  • e.g. ethene 
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Unsaturated hydrocarbons belong to which family of

  • alkenes
  • e.g. ethene
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What does unnsaturated mean?

  • an unsaturated hydrocarbon means that it contains one or more carbon to carbon double bond.
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finish the sentence. The amount of fossil fuel bei

  • 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.
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Name 4 things to remember when talking about fuels

  • 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
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finish the sentence.. when any fuel burns..

  • carbon dioxide and water vapour are formed
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Name 5 aspects of complete combustion.

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

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Name 3 aspects of incomplete combustion.

  • 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
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Why is carbon monoxide so dangerous?

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

  • 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.
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How do humans increase carbon dioxide levels?

  • deforestation
  • burning fossil fuels
  • using ossil fuels to make electricity
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Sulphur dioxide. How is it bad for the environment

  • it is created by burning fossil fuels
  • it dissolves with water to make dilute sulphuric acid
  • which is aa kind of acid rain
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Nitrous oxide. How is it bad for the environment?

  • it is formed by internal heat combustion engines
  • dissolves into water to form nitric acid
  • acid rain
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Describe the first phase of the early atmosphere.

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Describe phase two of the early atmosphere

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Describe phrase three of the early atmosphere

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What is photochemical smog?

  • 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.
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What is acid rain?

  • 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.
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What are thermoplastic polymers, and what are thei

  • 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)
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what are thermosetting polymers?


  • 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.
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What are the differences between HDPE and LDPE?

  • 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)
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Why should we use Gore-Tex and not nylon coated wa

  • 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.
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Give some physical properties of polymers.

  • 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.
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Name some problems with polymers.

  • 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
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why do we cook food?(4)

  • to kill microbes
  • makes it taste better, more flavorous
  • to improve texture
  • to make it digestible
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In many cases, a chemical reaction takes place.Nam

  • meat
  • fish
  • eggs

(all protein)

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What happens to proteins when they are heated?

  • they DENATURE.
  • they can never return to how they were.
  • the change is PERMANENT.
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Describe what happens to potatoes when they are co

  • 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.
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Give an example of thermal decomposition within co

  • 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.
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Most perfumes, food smells and solvents are made f

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