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28 Cards in this Set
- Front
- Back
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Fractional distillation |
Vapours cool as they rise through the column. They condense to form liquid when they reach a cool enough layer. Long hydrocarbon chains with the highest boiling points leave at the bottom because they require the most energy to break the intermolecular forces. The liquid falls and is piped out as fractions. |
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Cracking |
Converting large hydrocarbons into smaller useful fractions. You heat them to a high temp and pass them over a catalyst. Helps to match supply and demand. This can cause alkanes to crack into alkanes aswell. |
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Complete combustion |
When air is plentiful |
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Burning hydrocarbons |
Carbon atoms react with oxygen to produce CO2 Hydrogen atoms react with oxygen to produce water. You can test for CO2 if lime water turns milky and for water blue cobalt chloride turns pink Hydrocarbon + O2 > CO2 + H2O |
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Baking powder equation |
2NaHCO3 > Na2CO3 + H2O + CO2 Decomposition reaction |
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Emulsifiers |
The hydroponic end bonds with oil molecules. The hydrophilic end bonds to water. This stops droplets of oil or water forming so the mixture doesn't separate. |
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Volatility |
= how easily a liquid evaporates. Perfumes evaporate faster once applied to skin because they are warmer and so have more energy to overcome the iforces. |
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Solubility |
Depends on the the relative strength of the attractions between the - substance particles and solvent molecules - substance particles - solvent molecules The attractions between nail varnish particles and water are weaker than nail varnish particles and the water molecules so nail varnished will not dissolve. |
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Paints consist of... |
Pigment Binding medium - to stick paint to surface Solvent - thins paint to spread even |
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Emulsion paints |
Ingredients are dissolved in water which evaporates to leave colour. |
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Oil paints |
The hydrocarbon oil evaporates leaving the colour. Oxygen oxidises the hydrocarbon molecules forming a tough layer. |
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Colloids |
A mixture in which one substance is evenly dispersed in another as the particles are too small to settle. None of the substances are dissolved. (Paints are colloids) |
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Thermochromic pigments |
Sensitive to temp. Can be mixed with acrylic paint for even more colour changes. Kettles Baby spoons |
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Phosphorescent |
Absorb light and release over a period. Warning signs Clocks |
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Glow in the dark danger |
Radioactive substances like radium with phosphor are glow in the dark. The reaction will damage our cells and can cause cancer. |
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Incomplete combustion |
Shortage of air. Carbon monoxide and carbon (soot) are produced not CO2. |
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Factors to consider with fuel |
ACE PETS Available Cost Energy value Pollution Ease of use Toxicity Storage |
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Forming the atmosphere |
Volcanoes released huge volumes of gases that make up the atmosphere. The water vapour condensed to form oceans leaving CO2 mostly in the air. Plants converted the CO2 to O2 and large amounts dissolved in the ocean. |
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Gas levels in forming the atmosphere |
Oxygen increased Nitrogen increased CO2 decreased Ammonia decreased Methane decreased 78% N 21% O 0.035% CO |
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Photochemical smog |
NOx reacts with atmospheric pollutants. |
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Alkanes |
A family of hydrocarbons (ONLY carbon and hydrogen) Methane Ethane Propane Butane C n H 2n+2 Display formula-single covalent bond |
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Alkenes |
Another family of hydrocarbons. Ethene Propene etc. Display formula - a single double bond. |
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Bromine and alkenes |
Bromine reacts with alkEnes not alkAnes. Bromine water is orange but turns colourless when mixed with alkEnes. |
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Unsaturation |
AlkAnes are saturated compounds containing only single covalent bonds. AlkEnes are unsaturated compounds containing one double bond between carbon atoms. Addition reactions with bromine test for unsaturation. |
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Polymerisation |
High pressure and a catalyst make polymers from monomers. |
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Additional polymerisation |
Unsaturated alkene monomers form a saturated polymer. They are drawn the same but with a single bond between the carbons, square brackets around and new bongs protruding the brackets on either side. |
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Plastic strength |
Some polymer plastics are only attracted by weak iforces which are easily overcome. These plastics have a low melting point and stretch easily. Other polymer plastics have strong bonds betweeb them. The cross-links mean they have high melting points and are ridged. |
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Cooking potatoes |
Raw potatoes are tough, bitter and hard to digest Cooked potatoes are soft and sweet. When cooked the cell walls break losing the ridged structure and starch grains are released which absorb water to swell. |
