Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Dated 15 Oct 2004 Notes are copyrighted. Author : Mr Anthony Tang, Bowen Secondary School CHEMISTRY SUMMARY NOTES FOR ‘O’ LEVEL TOPIC MNEMONICS Experimental Techniques NIL REMARKS (Need to know about) - Separate insoluble substances from soluble substances. [i.e. Dissolution Filtration Saturation (Evaporation)/ Crystallisation] - Chromatography : separating soluble solutes using a suitable solvent (e.g different coloured inks) Elements, Mixtures & Compounds Chemical Formula NIL Cations H+ Cu2+ Fe2+, Fe3+ Zn2+ Structure of atoms - Definition of element, mixture and compounds. - 3 differences between mixtures and compounds Anions SO42SO32NO32OH- NIL *Chemical bonding Metal + Non-metal Non-metal + Non-metal - Memorise charges of elements that cannot be found using the Periodic Table. - Crossing of numbers to get the correct formula. - Charge of protons (+), electrons (-) and neutrons (0) - Electrons in shells while protons and neutrons in nucleus - Protons = electrons for a neutral atom (i.e all elements in the Periodic Table) - When protons ≠ electrons, atoms are charged. (that explains why electrons lost or gained) Ionic Covalent 3 differences between Ionic/ covalent compounds 1) Solubility in water / organic solvents 2) Electrical conductivity when molten or aqueous 3) Melting pt / Boiling pt 1 - Definition of ionic and covalent compounds - Draw electronic structure of ionic and covalent compounds. [Ionic – transfer of electrons, strong electrostatic forces of attraction between oppositely charged ions] [Covalent – sharing of electrons, weak intermolecular forces of attraction] Dated 15 Oct 2004 Notes are copyrighted. Author : Mr Anthony Tang, Bowen Secondary School TOPIC *Mole Concept MNEMONICS REMARKS FOUR-BOX RULE Name of substance Name of substance Para 2 STANDARD Mass Volume Mole No. of particles : : : : Ar/ Mr 24 dm3 at r.t.p 1 6.0 X 1023 atoms/ molecules STANDARD TO BE FOUND Bonds formed, heat released. (Exothermic) Heat absorbed, bonds broken. (Endothermic) STANDARD TO BE FOUND Para 2 GIVEN DATA Energy changes Para 1 Para 1 ANSWERS Exothermic : Heat released, temperature increase Endothermic : Heat absorbed, temperature decrease. Rates of reaction *Acids, bases and salts Factors affecting rates of reaction Surface Area to Volume Ratio Pressure Concentration Catalyst Temperature Gradient of curve affected by SPCCT Height of graph affected by amount and volume of substances. General way to identify chemicals through chemical formulae Acids : H in front Bases : OH or O behind Salts : Neither an acid or base Chemical formulae you must KNOW HCl - hydrochloric acid H2SO4 - sulphuric acid HNO3 - nitric acid *Chemical properties of acids Acid + Base Salt + Water Acid + Metal Salt + Hydrogen Acid + Carbonate Salt + Carbon Dioxide + Water NaOH KOH NH3 , NH4OH *Chemical properties of bases Base + Ammonium salt Salt + Ammonia + Water 2 - sodium hydroxide - potassium hydroxide - aqueous ammonia, ammonium hydroxide Dated 15 Oct 2004 Notes are copyrighted. Author : Mr Anthony Tang, Bowen Secondary School TOPIC Metals MNEMONICS REMARKS *Reactivity series of metals : Please : K (Potassium) Holiday Sue : Na (Sodium) Condo Can : Ca (Calcium) Must Move : Mg (Magnesium) Sell All : Al (Aluminium) Good Zombies : Zn (Zinc) Price Into : Fe (Iron) The : Sn (Tin) Loo : Pb (Lead) [Remember properties and uses of metals] Extraction of metals – react vigorously with water/steam and acid Normal font – moderate to mild with water/steam and acid Italicized – No reaction with water and acid In bold : H (Hydrogen) : Cu (Copper) : Hg (Mercury) : Ag (Silver) : Au (Gold) : Pt (Platinum) Ingredients added from the top of the Blast furnace Coke (C) Iron Ore (Fe2O3) Limestone (CaCO3) - Displacement of metals [The more reactive metal (head) ‘kick out’ the less reactive metal from the ‘gang’] ‘Kick out’ – Use displace instead. [N.B : When displacement of metals occurs, deposits appear.] Produce lots of CO2 C + O2 CO2 CaCO3 CaO + CO2 Change CO2 to CO CO2 + C 2CO Materials from the side of the Blast Furnace Air (O2) Fe2O3 reduced to CO Fe2O3 + 3CO 2Fe + 3CO2 (Swing from ‘tree’(3) to(2) ‘tree’(3)) Removal of impurities CaO + SiO2 CaSiO3 (molten slag) (Both are impurities) 3 Dated 15 Oct 2004 Notes are copyrighted. Author : Mr Anthony Tang, Bowen Secondary School TOPIC MNEMONICS Metals/ Non – metals REMARKS NIL Group I Elements - Reactivity increases as you move down the group. Group VII Elements - Reactivity decreases as you move down the group. Remember chemical and physical properties of Group I and Group VII elements (i.e displacement reactions, reaction with each other) Fractional distillation of crude oil Composition of air - The uses of the different fractions Peter Pan Never Kills Dead Fat Lying Bees Petroleum Gas (consists mostly of methane) Petrol Naphtha Kerosene Diesel Oil Fuel Oil Lubricating Oil Bitumen MUST KNOW THE PERCENTAGES BY HEART Nitrogen Oxygen Noble gas (mainly Argon) Carbon dioxide Water vapour 79% 20% <1% 0.03% Variable - In a reaction involving air, when combustion takes place, oxygen is used up. {therefore, about 80% gas left} - Name pollutants in air and state one harmful effect each. (SO2, Pb compounds, CO, CFC) - How is acid rain formed? 4 Dated 15 Oct 2004 Notes are copyrighted. Author : Mr Anthony Tang, Bowen Secondary School TOPIC MNEMONICS REMARKS Organic Chemistry Mummy Eats Peanut Butter Pancake Happily MetEthPropButPentHex- 1-Carbon 2-Carbon 3-Carbon 4-Carbon 5-Carbon 6-Carbon - Remember general formula of alkanes, alkenes, alcohols and carboxylic acid. Alkanes Alkenes Alcohols Carboxylic acid CnH2n+2 CnH2n CnH2n+1 OH CnH2n+1 COOH - *To differentiate alkenes, use bromine water. Alkane - Bromine water remains orangered. Alkene - Bromine water decolourised. Organic Chemistry Making of alcohol - Know the physical and chemical properties of alkenes and alcohols Ingredients required 1) Sugar Solution 2) Yeast 3) Anaerobic condition (i.e no oxygen) 4) Temperature : 30 – 35°C Chemical properties of alkenes -Reaction with bromine -Reaction with hydrogen -Reaction with itself (addition polymerisation) Alcohol is formed from the reaction between an alkene and steam. Catalyst : Phosphoric (V) acid Chemical properties of alcohol -Burn in air to form carbon dioxide and water -React with carboxylic acid to form ester and water 5 Dated 15 Oct 2004 Notes are copyrighted. Author : Mr Anthony Tang, Bowen Secondary School TOPIC Organic Chemistry (Macromolecule) MNEMONICS REMARKS In addition polymerisation, make the molecule into the shape of an H in relation to C=C double bond. Once that is done, remove centre line, extend 2 lines to the sides, bracket followed by subscript n Chemical properties of carboxylic acid -React with alcohol to produce ester and water. List 3 uses of plastics. O || -C-O- Synthetic Ester linkage Terylene O || -C-N| H Amide linkage Nylon Natural Fats Protein Nylon : same letters when the box is covered. N- Amide C- -N C- -C : different letters when the box is covered. -N C- -N TER in TERylene, you are reminded of esTER 6 List 3 advantages and disadvantages of using plastics.