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72 Cards in this Set
- Front
- Back
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Food additives (4 points) |
• Food colouring - makes food change colour, more appealing • Flavour enhancers- bring out taste and smell of food, but they have no taste themselves. • Antioxidants - preserve food by stopping them oxidising • Emulsifiers - help water and oil mix in things like mayonnaise |
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What are the parts of an emulsifier? (2 points) |
• hydrophilic (water-loving) head • hydrophobic (hates water, loves fat/oil) tail |
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How to emulsifiers cause emulsification? (4 steps) |
1. hydrophilic head bonds to water molecules bonds to water molecules 2. hydrophobic tail bonds to oil molecules 3. when mixed, oil forms droplets surrounded by emulsifier molecules with the hydrophilic head facing outwards. 4. the hydrophilic (water hating) heads of the emulsifier molecules facing outwards from the oil droplet repel other oil droplets, so they can never mix and separate out from water. |
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Why do we cook proteins like eggs and meat? (2 points) |
• kills harmful microbes on the food (this applies to all cooking processes) • the high temperature causes the proteins to denature and change shape, changing their texture and making it more edible |
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Why cook potatoes? (2 points) |
• we can't digest cellulose in cell wall, cooking ruptures the cell walls. • starch swells up, spreads out, potato gets softer, more flexible = easier to digest. |
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What process does baking power undergo when heated? (2 points) |
• thermal decomposition. • the carbon dioxide released is what causes cakes to rise |
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How do you test for carbon dioxide? (1 step) |
• put it in limewater - if turns cloudy then carbon dioxide is present. |
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What properties do perfumes need? (5 points) |
• easily evaporates - so we can smell them • non-toxic - won't poison you • doesn't react with water - or else will react with sweat • doesn't irritate the skin • insoluble - or would wash off in sweat/rain. |
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Is it ok to test perfumes on animals? (2 points) |
• Yes - so we know they won't harm humans. • No - unethical to cause suffering just for a cosmetic (and results may not be conclusive) |
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Features of solids (3 points) |
• strong forces between particles • keeps a definite shape and volume (particles don't move from positions) • particles vibrate about their positions |
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Features of liquids (3 points) |
• some force of attraction between particles • don't keep a definite shape but keep a definite volume • particles constantly move with random motion |
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Features of gases (3 points) |
• no force of attraction between particles • no definite shape of volume (fill any container) • particles move constantly with random motion |
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How does evaporation and volatility work? (4 points) |
• when a liquid is heated heat energy causes particles to move faster • some faster than others • fast moving particles at surface will overcome forces of attraction of others and escape, This is evaporation. • how easily evaporation happens is it's volatility (perfumes are volatile) |
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Why doesn't nail varnish dissolve in water? (2 points) |
• water molecules more strongly attracted to each other than nail varnish molecules • nail varnish molecules more strongly attracted to each other than water molecules - doesn't form solution |
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Why is nail varnish soluble in acetone? (1 point) |
• attraction between acetone and nail varnish molecules stronger than the forces of attraction holding the two substances together |
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Name the parts of paint (3 points) |
• pigment - gives paint colour • binding medium - carries the pigment, when turns solid sticks pigment to surface • solvent - thins paint, makes easier to spread |
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Why are paints colloids and why don't particles separate out in colloids? (2 points) |
• colloids made of tiny particles of one stuff mixed in with another • particles don't settle because particles are so small, don't have enough mass |
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How do emulsion paints dry? (2 points) |
• solvent (water) evaporates, leaving behind thin solid film of binder and pigment. dries quickly • fast drying, produce no harmful fumes = use to paint inside walls |
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How do oil paints dry? (3 points) |
• solvent (organic compound) evaporates, producing harmful fumes. • oil is oxidised, leaving binding medium (oil) and pigment in solid layer. longer to dry • glossy and hardwearing, used for outside doors, metalwork. |
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Uses of thermochromatic pigments (5 points) |
• kettles - change colour as water boils • baby products & spoons - to warn parents if too hot • drink mugs - tell you drink is too hot • make basic thermometers you can stick on your forehead • mood rings - for entertainment |
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How do phosphorescent pigments work? (1 point) |
• absorb artificial/ natural light in molecules, release it slowly as light energy over time (used to be made with radioactive paints but these gave people cancer) |
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Alkenes (3 points) |
• unsaturated (one or more double covalent bond(s) that can open up) • so they're more reactive than alkanes • first three alkenes are ethene, propene and butene |
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Bromine water test (2 points) |
• bromine water turns colourless if there is an alkene mixed into it • this is bc alkenes are unsaturated - their double bonds can open up |
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Fractional distillation column - where fractions drain out & their uses (top to bottom) (7 points) |
- LPG (burning fuel) - Petrol (fuel for cars, combusted easily) - Naphtha (fuel) - Kerosene (paraffin) (fuel for aeroplanes) - Diesel (lorry fuel) - Oil (heating oil, fuel oil, lubricating oil) - Bitumen (road surfacing, very high melting/boiling point) |
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How to hydrocarbon properties change as they get longer? (4 points) |
• less flammable • higher boiling/melting points • less volatile • more viscous |
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Why do bigger hydrocarbons have higher boiling points? (2 points) |
• stronger forces of intermolecular attraction • this is because they're longer - more points at which there can be attraction, so if weak in one place there may be other areas of the molecule where the forces of attraction are strong enough to stop it evaporating. |
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Conditions for cracking (3 points) |
• high pressure • high temperature • aluminium oxide catalyst |
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Why use cracking? (2 points) |
• larger alkanes like bitumen where supply> demand can be broken down into smaller alkanes where supply • useful alkenes produced used to make polymers |
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Disadvantages of fossil fuel combustion (5 points) |
• as stocks are used up, countries may decide to stop selling them and keep them for themselves • countries with more FF will have power over those that don't; tension & wars • UK may have to rely on politically unstable countries, we could get cut off • oil tankers can spill and cause oil slicks, oil gets in bird feathers and stops them from flying, kills them • detergents used to clean them up are toxic and kill marine life |
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What to consider when choosing a fuel (7 points) |
• energy value • availability • storage (is it flammable, explosive) • cost • toxicity • ease of use • pollution/pollutants released |
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Properties of weak and strong intermolecular forces in plastics? (2 points) |
• weak = chains free to slide over each other. plastic easily stretched with low melting point |
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What are different polymers used for? (4 points) |
• strong, rigid polymers like high density polyethene used to make plastic milk bottles • light, stretchable plastics like low density polyethene used to make plastic bags, squeezy bottles (side note: very low melting point) • PVC strong and durable, can be either rigid or stretchy. rigid = window frames, piping stretchy = synthetic leather • Polystyrene foam used to package things (cushion them) and for disposable coffee cups. (good thermal insulator) |
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How does GORE-TEX work, and why is nylon worse? (3 points) |
• thin sheet of plastic called PTFE laminated onto layer of another fabric like nylon - PFTE becomes sturdier • PFTE has tiny holes that let water vapour from sweat through, but holes not big enough for rain to so is waterproof. • nylon is waterproof but doesn't let water vapour through so sweat condenses on inside, very wet & uncomfortable. |
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Adv. and disadv. of using landfill to deal with plastics (7 points) |
Adv: cheap, oft use disused land like old mines, quarries, easily accessible
Disadv: plastic takes long time to biodegrade, waste of land & plastic, soil may become contaminated, landfill released methane (greenhouse gas) |
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Adv. and disadv. of using incineration/combustion to deal with plastics (5 points) |
Adv: reclaims some energy used to produce plastics, reduced use of fossil fuels, quick & easy
Disadv: releases sulfur dioxide (acid rain) and hydrogen chloride/cyanide (toxic), catalytic converters used to stop this are expensive |
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Adv. and disadv. of using recycling to deal with plastics (6 points) |
Adv: no plastic wasted, reduced fossil fuels and raw material usage, make new products
Disadv: expensive difficult and time consuming, not all plastics can be recycled, consumers not educated on recycling (can't sort plastics out well) |
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What is a covalent bond? (1 point) |
• Chemical bond created by sharing one or more electrons. |
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Alkanes (3 points) |
• saturated (only single covalent bonds between carbon atoms) • won't form polymers bc no double bonds to open up • first four are methane, ethane, propane, butane |
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What are double covalent bonds? (1 point) |
• two atoms sharing two pairs of electrons |
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How do phosphorescent pigments work? (1 point) |
• absorb artificial/ natural light in molecules, release it slowly as light energy over time (used to be made with radioactive paints but these gave people cancer) |
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Alkenes (3 points) |
• unsaturated (one or more double covalent bond(s) that can open up) • so they're more reactive than alkanes • first three alkenes are ethene, propene and butene |
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Bromine water test (2 points) |
• bromine water turns colourless if there is an alkene mixed into it • this is bc alkenes are unsaturated - their double bonds can open up |
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Fractional distillation column - where fractions drain out & their uses (top to bottom) (7 points) |
- LPG (burning fuel) - Petrol (fuel for cars, combusted easily) - Naphtha (fuel) - Kerosene (paraffin) (fuel for aeroplanes) - Diesel (lorry fuel) - Oil (heating oil, fuel oil, lubricating oil) - Bitumen (road surfacing, very high melting/boiling point) |
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How to hydrocarbon properties change as they get longer? (4 points) |
• less flammable • higher boiling/melting points • less volatile • more viscous |
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Why do bigger hydrocarbons have higher boiling points? (2 points) |
• stronger forces of intermolecular attraction • this is because they're longer - more points at which there can be attraction, so if weak in one place there may be other areas of the molecule where the forces of attraction are strong enough to stop it evaporating. |
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Conditions for cracking (3 points) |
• high pressure • high temperature • aluminium oxide catalyst |
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Why use cracking? (2 points) |
• larger alkanes like bitumen where supply> demand can be broken down into smaller alkanes where supply • useful alkenes produced used to make polymers |
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Disadvantages of fossil fuel combustion (5 points) |
• as stocks are used up, countries may decide to stop selling them and keep them for themselves • countries with more FF will have power over those that don't; tension & wars • UK may have to rely on politically unstable countries, we could get cut off • oil tankers can spill and cause oil slicks, oil gets in bird feathers and stops them from flying, kills them • detergents used to clean them up are toxic and kill marine life |
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What to consider when choosing a fuel (7 points) |
• energy value • availability • storage (is it flammable, explosive) • cost • toxicity • ease of use • pollution/pollutants released |
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Properties of complete combustion (4 points) |
• releases a lot of energy • burns with a clean, blue flame • only releases 2 harmless waste products (water & carbon dioxide - no issue if room well ventilated) • happens when there's plenty of oxygen available |
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Properties of weak and strong intermolecular forces in plastics? (2 points) |
• weak = chains free to slide over each other. plastic easily stretched with low melting point |
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Properties of incomplete combustion (5 points) |
• happens when not enough oxygen is present • less energy released • burns with yellow flame • releases carbon (soot) and carbon monoxide as waste products • carbon monoxide very dangerous as odourless, colourless and poisonous (why we have regular checks on gas appliances at home) |
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What are different polymers used for? (4 points) |
• strong, rigid polymers like high density polyethene used to make plastic milk bottles • light, stretchable plastics like low density polyethene used to make plastic bags, squeezy bottles (side note: very low melting point) • PVC strong and durable, can be either rigid or stretchy. rigid = window frames, piping stretchy = synthetic leather • Polystyrene foam used to package things (cushion them) and for disposable coffee cups. (good thermal insulator) |
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How does GORE-TEX work, and why is nylon worse? (3 points) |
• thin sheet of plastic called PTFE laminated onto layer of another fabric like nylon - PFTE becomes sturdier • PFTE has tiny holes that let water vapour from sweat through, but holes not big enough for rain to so is waterproof. • nylon is waterproof but doesn't let water vapour through so sweat condenses on inside, very wet & uncomfortable. |
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Conditions for cracking (3 points) |
• high temperature • aluminium oxide catalyst |
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Why use cracking? (2 points) |
• larger alkanes like bitumen where supply > demand can be broken down into smaller alkanes where supply • useful alkenes produced used to make polymers |
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Adv. and disadv. of using recycling to deal with plastics (6 points) |
Adv: no plastic wasted, reduced fossil fuels and raw material usage, make new products
Disadv: expensive difficult and time consuming, not all plastics can be recycled, consumers not educated on recycling (can't sort plastics out well) |
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What is a covalent bond? (1 point) |
• Chemical bond created by sharing one or more electrons. |
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Alkanes (3 points) |
• saturated (only single covalent bonds between carbon atoms) • won't form polymers bc no double bonds to open up • first four are methane, ethane, propane, butane |
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What are double covalent bonds? (1 point) |
• two atoms sharing two pairs of electrons |
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Evolution of the atmosphere (first billion years) (3 points) |
• the earth's surface was originally molten and any atmosphere boiled away • it eventually cooled and a thin crust formed, volcanoes erupted releasing carbon dioxide, steam and ammonia • water vapour condensed to form oceans, early atmosphere mostly carbon dioxide |
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evolution of the atmosphere (the next 2 billion years) (5 points) |
• early carbon dioxide dissolves into the oceans • green plants evolved and photosynthesised, reducing carbon dioxide and making oxygen levels rise • carbon dioxide gets locked up in fossil fuels and sedimentary rocks • nitrogen has released by denitrifying bacteria and ammonia reacting with oxygen • it built up because it is so unreactive |
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evolution of the atmosphere (the past 1 billion years) (4 points) |
• buildup of oxygen kills early organisms that respire using carbon dioxide • oxygen allowed evolution of more complex organisms that made use of it • oxygen creates ozone layer, blocked UV rays from the Sun and even more complex organisms can evolve • almost no carbon dioxide left |
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Composition of the atmosphere? (4 points) |
• Nitrogen 78% • Oxygen 21% • Argon (and other noble gases) 1% • carbon dioxide 0.035% |
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What adds carbon dioxide to the atmosphere? (4 points) |
• respiration of animals and plants releases it • combustion of fossil fuels (rising use of combustion due to population pressures, more energy demand per person as countries develop) • decomposition of dead material (decomposers respire as they chemically break it down) • as the oceans heat up due to global warming they release carbon dioxide that was previously dissolved in them |
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what removes carbon dioxide from the atmosphere? (1 point) |
• photosynthesis (although this happens less due to deforestation for resources, mining, roads, space for housing/farming) |
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List issues of exponential population growth (5 points) |
• food shortages • land shortages (overcrowding --> deforestation) • more disease spreads, can lead to pandemics • exponentially rising carbon dioxide levels due to rising energy demands • generally more resource pressure - supply |
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Causes and effects of acid rain (4 points) |
• sulfur dioxide from fossil fuels w sulfur impurities • nitrogen oxides caused by reaction of air + nitrogen with heating, also in combustion engines of cars • lakes become acidic, plants & animals die • damages limestone buildings, stone statues, corrodes metal |
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List issues of exponential population growth (5 points) |
• food shortages • land shortages (overcrowding --> deforestation) • more disease spreads, can lead to pandemics • exponentially rising carbon dioxide levels due to rising energy demands • generally more resource pressure - supply |
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Causes and effects of acid rain (4 points) |
• sulfur dioxide from fossil fuels w sulfur impurities • nitrogen oxides caused by reaction of air + nitrogen with heating, also in combustion engines of cars • lakes become acidic, plants & animals die • damages limestone buildings, stone statues, corrodes metal |
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How is photochemical smog caused? (3 points) |
• Sunlight acts on oxides of nitrogen • Oxides react with the air to form ozone at ground level • This causes breathing difficulties, headaches and tiredness. It can kill people with respiratory diseases like bronchitis. |
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catalytic converters |
• used to reduce carbon monoxide and nitrogen oxide released by cars • use a catalyst of rhodium or platinum • convert them to nitrogen and carbon dioxide |
