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Infection and response
Organisation
Cell biology
Biological molecules
Homeostasis and response
Responding to change (a2 only)
Energy transfers (a2 only)
The control of gene expression (a-level only)
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
Cells
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1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
Britain & the wider world: 1745 -1901
Inter-war germany
World war one
2n revolution and dictatorship: russia, 1917-1953
World war two & the holocaust
1l the quest for political stability: germany, 1871-1991
The cold war
2j america: a nation divided, c1845-1877
Medieval period: 1066 -1509
The fight for female suffrage
2m wars and welfare: britain in transition, 1906-1957
2d religious conflict and the church in england, c1529-c1570
Britain: 1509 -1745
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02/04/2023
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21 " UNIT 3 CHEMISTRY IN SOCIETY moles Volume mv m gfm ✓ molar volume mass n gram formula mass moles C concentration specific heat capacity of water (4.18) C V En T moles X change in energy mass of volume change At Xin templ water Getting the most from reactants industrial processes used to : maximise profit minimise impact on environment. economic influences. + availability + sustainability. + cost of feedstock + opportunities for recycling. + marketability of by-products. + product yield. · environmental considerations + minimising waste + avoid use / production of toxic substances clesign biodegradable products raw materials - converted to feedstock to use in reactors feedstocks- simple chemicals/mixtures from raw mats. excess calculations! O ratio molar Have Pe to ensure that a costly reactant is converted into product excess can be re-used leconomical) 3 Need example 50cm³ of CO burned in 20cm³ of Oxygen.... Calculate what gas is in excess. 200 0₂-200₂ + 50cm³: 20cm ³ 40cm³: 20 cm³ 50-40 10 10cm³: X Excess limiting 3 O Percentage Yield • what you actually make vs the desired products Z molar ratio m of procluct example in of reactant yield = actual ethanol - 46g a student used 2.5g of ethand and excess ethanoic acid to produce 2.9g of ethyl ethancate 7 yield n = 2.5 46 ethanol 0.054 theoretical A t ethanoic acid = ethyl ethanoate -889 0.054 m = 0.054 x 88 = H ethyl ethanoate 0.054 100 4.78 (theoretical) 2.9 4.78 60.63% ×100 water Atom economy. 2 3 % •Shows how successfully reactants are converted into products. example methane reacts with steam to produce hydroge Calculate the atom economy for the formation of hydrogen. CH4 (9) + Hy09) H₂2₂0 - 16g 189 3 (H₂) CH4 + 3(2) 16+ 18 6 34 H₂0 x x 100 100 x 100 mass desired product x 100 total mass reactants = CO(g) + = 289 17.65% 3H₂ (9) = 29 holar volume. I calc ratio volume occupied by one mole of gas at the same temperature and pressure 3) calc V example molar dishwater tablet produces 0.051g of...
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hydrogen peroxide (34g). Calc volume of oxygen produced when 0.051g of hydrogen peroxide decomposes 2 H₂O₂ +17 →→ 2H1 ₂0 (1) + 0₂ (9) n = 0.051 34 = 0.0015 2 H₂O₂ →→ 2 : 015 V= +0₂ 000 75 0.018 0.00075 X 24 Controlling the rate factors affecting rate of reaction. 4 temperature 4 concentration. 4 pressure + particle size + catalyst 4 concentration - increases no. of particles in Solution •°• increase in successful collisions increasing rate. pressure increase likliness of particles colliding • increase successful collisions & rate particle size - increases surface area .. increases collisions, increasing rate 4 temperature - increases Rinetic energy. collide with more energy & rate. Average rate rate = + r = AQ At time = 1 t Collision Theory for atoms/molecules/particles to react, they must collicle 2 factors required for successful collisions to take place : 4 activation energy La geometry of reactants 10 Rinetic energy greater than the activation energy (EK > Ea) 2 the correct collision geometry (particles to be facing the correct way) Activation minimum amount of energy required energy for particles to collide - Activated high energy, unstable arrangement of complex atoms formed at intermediate stage of reaction. - enthalpy diagrams Chemical energy -AH No. of particles Enthalpy (AH). 2 exothermic Exothermic Endothermic еав ea F AH t сав enclothermic the difference in energy between the reactants and products. reaction which energy is released reaction that takes in heat energy ea with catalyst ea without catalyst Kinetic energy catalyst - increases rate without being used up in the reaction, by lowering activation energy. enthalpy of combustion. • the energy released when one mole of a substance burns completely in oxygen. molar bond enthalpy thermometer Imean bond enthalpy draught shield. bond enthalpies R-P bond breaking = endothermic (tve) bond forming = exothermic (-ve) copper can + water spirit burner energy required to break one mole of bonds in a diatomic molecule in the gaseous state. average energy required to break one mole of bonds for a bond which occurs in a variety of compounds. - flip • used to calculate enthalpy changes to eqn match 2 times -egn tu match Hess's law add all он example Co₂ (1) + 30₂ (9) ((S) + O₂ (g) →→→ S (s) + O₂ (g) + C (S) + 25 (S) H (0₂ (9) + 250₂ (9) CO₂ (9) SO₂ (g) CS₂ (1) C(s) + 25(S) → CS₂ (1) CS₂ (1) + ((S) + 25(S) - 393.5 ·296.8 87.9 1075 ΔΗ 04 S (5) + 0₂ (9) SO₂ (9) 25 (s) + 20₂(g) + 250₂ (9) = - 393.5 -296.8 +87.9 +87.9 -87.9 -296.8 x2 Equilibria only occurs in reversible reactions • used to maximise profit by favouring products. + rate of forward rate of backwards + concentration of reactants/products are constant. Changing equilibria position. ● Concentration increase conc of reactants cecrease conc of reactants increase conc of products decrease cone of products temperature increase temp. decrease temp shifts right. Shifts Left Shifts left shifts right shifts to endothermic shifts to exothermic pressure increase pressure shifts to side with fewer gas moles clecrease pressure shifts to side with most gas moles catalyst increases rate of forward and reverse reaction equally therefore cloesn't affect position. 0 Chemical Analysis cbromatography. used to separate mixtures based on their solubilit and Size types of chromatography. paper gas Paper Chromatography • mobile phase - solvent (thing that moves) Stationary phase-paper (thing that moves on) D retention time time taken for a component to trave through apparatus Size of molecule the larger the molecule the longer it takes to travel