chemistry
- <!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:1778865057; mso-list-type:hybrid; mso-list-template-ids:1098835222 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:54.0pt; mso-level-number-position:left; margin-left:54.0pt; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} --> COOKING
- FOOD ADITIVES
- SMELLS
- MAKING CRUDE OIL USEFUL
- MAKING POLYMERS
- USING CARBON FUELS
- ENERGY
- Created by: JESSICA GODFREY
- Created on: 28-02-10 13:35
COOKING
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:1778865057; mso-list-type:hybrid; mso-list-template-ids:1098835222 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:54.0pt; mso-level-number-position:left; margin-left:54.0pt; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
· Some foods must be cooked: it kills harmful microbes with high temps, improves the taste/texture, makes it easier to digest
· The final product is different because of chemical reactions
· Irreversible change, requiring energy, meat and eggs are high in protein, when an egg is heated, protein molecules change shape – denaturing,
· Potatoes are carbohydrates containing cellulose which forms cell walls around starch, so uncooked potatoes are difficult to digest, cooking breaks down the walls and releases the starch which becomes a gel by absorbing water
· Baking powder is a raising agent (contains sodium hydrogencarbonate), this decomposes when baked to produce CO2 which rises making ‘bubbles’
· Limewater (calcium hydroxide) can be used to test CO2 as it turns cloudy
FOOD ADITIVES
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:1878394900; mso-list-type:hybrid; mso-list-template-ids:686877236 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:54.0pt; mso-level-number-position:left; margin-left:54.0pt; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
· Additives have to be approved of safety, all approved additives have E-numbers
· Emulsifiers: oil + water don’t mix, adding an emulsifier makes an emulsion (+shaking), emulsifier molecules have a hydrophilic head which has an ionic charge and an hydrophobic tail, the heads repel each other due to their charge
· Active or intelligent packaging is used to preserve foods, keeping out oxygen and water helps stop bacteria growing, there are 2 ways of controlling free rad. no.’s
· 1:Oxygen scavengers: chemicals are placed in packaging that remove oxygen and so prevent any oxygen reacting with it creating harmful free radicals
· 2:Antioxidants in the packaging combine with free radicals in the food before they breakdown the food/packaging
· Some film packaging lets oxygen in but ethene (which causes fruit to ripen) out
· Cans can heat/cool their contents when opened and widgets in beer cans froth it
`
SMELLS
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:74203461; mso-list-type:hybrid; mso-list-template-ids:1439334198 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
- Perfumes can be made from esters which are made by blending together natural oils or made synthetically, esters are also used as flavouring agents and solvents
- Mixtures of esters are very concentrated and are diluted by adding solvents
- Perfumes are mainly used in everyday products like polishers and air refreshers
- Organic acid + alcohol ® ester + water, (ethanoic acid + ethanol ® ethyl ethanoate)
- Perfumes: need to evaporate - volatile, be non-toxic, non-irritant, insoluble in water
- High volatility – weak attraction, high energy
- Esters can be used as solvents (solution = solvent + solute [that do not separate]), they dissolve many substances which don’t dissolve by water e.g. NVR
MAKING CRUDE OIL USEFUL
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:1646859419; mso-list-type:hybrid; mso-list-template-ids:1140632810 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
- Crude oil formed when small sea creatures and plants died and buried, formed in high temps. and pressures and in absence of air
- Oil can be forced through cracks and low b.p. hydrocarbons evaporate forming pitch
- Fractions (of similar b.p.): bitumen, fuel oil, heating oil, paraffin, diesel, petrol , LPG
- Covalent bonds between H and C are strong, longer chains = higher b.p.
- Cracking: alkane --> smaller alkane + alkene
MAKING POLYMERS
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:2052096; mso-list-type:hybrid; mso-list-template-ids:-1691739606 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
- Polymers are long chain molecules – a single unit is a monomer e.g. Poly(ethene) is lots of ethene monomers in a chain
- Alkanes = CnH2n+2, single covalent bonds only – so they are saturated
- Alkenes = CnH2n, at least one C=C covalent bond – so they are unsaturated
- Bromine water goes from yellow to clear if unsaturated
- Addition polymerisation is joining monomers by a series of addition reactions
<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->
USING CARBON FUELS
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:1644693613; mso-list-type:hybrid; mso-list-template-ids:-905965154 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
- Fuels react with oxygen to make energy, there are many with different properties
- Complete combustion = methane + oxygen --> carbon dioxide + water
- Incomplete = methane + oxygen --> carbon monoxide + carbon (soot) + water
- Complete is better: less soot, more heat, CO (poisonous is not produced
ENERGY
<!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0; mso-font-charset:2; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:0 268435456 0 0 -2147483648 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:Arial; mso-ansi-language:EN-GB; mso-fareast-language:EN-GB;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} /* List Definitions */ @list l0 {mso-list-id:829325100; mso-list-type:hybrid; mso-list-template-ids:520229280 1089130988 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1 {mso-level-number-format:bullet; mso-level-text:; mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt; font-family:Symbol; color:windowtext;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} -->
- Exothermic/endothermic – give out/take in energy, bond forming is exothermic, bond breaking is endothermic. Combustion is exothermic in O2
- Calorimeter(metal can which measures the heat)
- Energy = mass(kg) x s.h.c.(4.2 for water) x temp. change(°C)
- Energy per gram(J/g) = energy supplied(J) / mass of fuel burned(g)
Comments
No comments have yet been made