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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Mon, 08/05/2023 08:15 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Fri, 05/05/2023 14:49 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Fri, 05/05/2023 13:49 (1 Year ago) |
Item: Bug gem, fighting gem, grass gem, water gem, fire gem, magnetic bait Quantity: 245, 484, 170, 74, 110, 12 Total: 755,100 PD (you can check again on calc, i could be wrong) Tips: Random evo stone [Read more] |
Darknight07 OFFLINE Forum Posts: 37 |
Posted: Thu, 04/05/2023 08:13 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Fri, 28/04/2023 14:22 (1 Year ago) |
Item: Mystery box pink, mystery key brown, mystery key red, mystery key green, mystery key gold Quantity: 5 in total (46975 pd) [Read more] |
Darknight07 OFFLINE Forum Posts: 37 |
Posted: Fri, 28/04/2023 13:40 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Fri, 28/04/2023 13:18 (1 Year ago) |
Item(s): water gems Quantity: 224 Total: 224k PD Tips: an evolution item :) [Read more] |
Darknight07 OFFLINE Forum Posts: 37 |
Posted: Fri, 28/04/2023 11:13 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Thu, 27/04/2023 15:03 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Wed, 26/04/2023 14:34 (1 Year ago) |
Title: Chemistry IGCSEElectrolysis- Molten lead bromide: PbBr2 Pb2+ + 2e- -> Pb (Cathode) 2Br- -> Br2 + 2e- (Anode) Concentrated aqueous sodium chloride: NaCl 2H2O + 2e- -> H2 + 2OH- 2Cl- -> Cl2 + 2e- (Anode) The brine (salt water) will turn into sodium hydroxide which is alkaline since Na+ and OH- ions are left in the solution Molten sodium chloride: NaCl Instead of hydrogen and hydroxide ions, Na metal and Cl gas will be produced When using copper electrodes during the electrolysis of copper (II) sulfate (CuSO4), the solution will turn from blue to colourless as the copper is removed and pure copper will gather at the cathode (the anode contains a impure sample of copper). Fuel cells: Only consider hydrogen+oxygen fuel cells in ig! Enthalpy- Breaking bonds takes in energy Creating bonds releases energy CHEMICAL REACTIONS- Copper(II) sulfate: white to blue after addition of water Cobalt(II) chloride: blue to pink after addition of water Haber process N2+3H2->2NH3 The hydrogen comes from methane: CH4+H2O->3H2+CO CO+H2O->CO2+H2 The nitrogen comes from the air Conditions: -450 degrees celsius -200 atm -Iron catalyst Contact process 2SO2 + O2 ->2SO3 The sulfur comes from burning sulfur or roasting sulfur ores The oxygen comes from the air Conditions: -450 degrees celsius -2 atm -Vanadium(V) oxide Oxidation number -Oxidation number of elements in their uncombined state is zero -The oxidation number of a monoatomic ion is the same as the charge on the ion -The sum of the oxidation numbers in a compound is zero -The sum of the oxidation numbers in an ion is equal to the charge on the ion -Group 1 elements are always +1 -Group 2 elements are always +2 -Fluorine is always -1 -Hydrogen in always +1 except in metal hydrides where it is -1 -Oxygen is always -2 except in peroxides where it is -1 and F2O where it is +2 Metals- Reactions with... Dilute acids: Mg+2HCl->MgCl2+H2 Metal+acid->Salt+hydrogen Cold water: 2Na+2H2O->2NaOH+H2 Metal+water->Base+hydrogen Oxygen: 2Mg+O2->2MgO Metal+oxygen->Metal oxide Steam: Mg+H2O->MgO+H2 Metal+steam->Metal oxide+hydrogen Brass is a mixture of zinc and copper, stainless steel is a mixture of iron, carbon, chromium, nickel and some other metals. Reactivity series of metals: Potassium->Sodium->Calcium->Magnesium->Aluminium->Carbon->Zinc->Iron->Hydrogen->Copper->Silver->Gold Extraction of metals from their ores: Iron from hematite 1. Burning coke to produce heat and carbon dioxide C+O2->CO2 2. Reduction of carbon dioxide to carbon monoxide C+CO2->2CO 3. Reduction of iron(III) oxide by carbon monoxide Fe2O3+3CO->2Fe+3CO2 Slag from limestone 1. Thermal decomposition of calcium carbonate to produce calcium oxide CaCO3->CaO+CO2 2. Reaction of calcium oxide with silicon oxide CaO+SiO2->CaSiO3 Aluminium from bauxite 1. Aluminium ore is treated to form aluminium oxide (Al2O3) 2. Extraction is only possible through electrolysis because aluminium's reactivity is higher than carbon. However, electrolysis requires aluminium oxide to be molten. Cryolite will reduce the melting point of Al2O3, achieving the electrolysis of the compound. Cathode: 2Al3+ + 6e- -> Al2 Anode: 2O2- -> O2 + 4e- Environment- -Sedimentation and filtration to remove solids -Carbon to remove tastes and odours -Chlorine to remove microbes Greenhouse gases cause global warming by trapping the thermal energy. After the sun's rays reach the Earth's surface, a lot of it is reflected back into the atmosphere. The gases will trap the reflected rays and reduce the thermal energy loss into space. Nitrogen oxide: They can cause photochemical smog, acid rain, and respiratory problems. Organic chemistry- A homologous series is a family of similar compounds with similar chemical properties due to the presence of the same functional group. In a fractional distillation column for petroleum, the fractions obtained from bottom to top have: -Decreasing chain length -Higher volatility (evaporation) -Lower boiling points (this is why they can be separated) -Lower viscosity Hydrogenation: Alkene+hydrogen(with a nickel catalyst)->Alkane Hydration: Alkene+steam(with an acid catalyst)->Alcohol How to manufacture ethanol? 1. Fermentation C6H12O6->2C2H5OH+2CO2 Conditions: 25-35 degrees celsius+no oxygen present 2. Catalytic addition of steam to ethene C2H4+H2O->C2H5OH Conditions: 300 degrees celsius+60 atm+acid catalyst (e.g. acidified potassium manganate) Ethanol can be converted into ethanoic acid by oxidising it using acidified potassium manganate. C2H5OH+2O(from potassium manganate)->CH3COOH+H2O Reactions of ethanoic acid with... Metal: 2CH3COOH+Mg->(CH3COO)2Mg+H2 Ethanoic acid+metal->Salt+hydrogen Base: CH3COOH+NaOH->CH3COONa+H2O Ethanoic acid+base->Salt+water Carbonates: 2CH3COOH+Na2CO3->2CH3COONa+CO2+H2O Ethanoic acid+carbonate->Salt+water+carbon dioxide Condensation polymerisation: Polyesters are formed from dicarboxylic acids (H-O-C=O) and diols (H-O) Polyamides are formed from dicarboxylic acids (H-O-C=O) and diamines (H-N-H) -Proteins are natural polyamides formed from amino acid monomers with an amine functional group on one side and a carboxyl group on the other side. The carbon in the middle also connects to a hydrogen and a long carbon chain. [Read more] |
Darknight07 OFFLINE Forum Posts: 37 |
Posted: Wed, 26/04/2023 14:05 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Sun, 23/04/2023 23:45 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Sun, 23/04/2023 11:26 (1 Year ago) |
Pokemon to Offer: 3 How much do you think that I should pay you?: Is 2000 PD ok? Anything else?: Check gts [Read more] |
Darknight07 OFFLINE Forum Posts: 37 |
Posted: Sat, 22/04/2023 12:53 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Sat, 22/04/2023 05:41 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Sat, 22/04/2023 05:12 (1 Year ago) |
Hatched! Its fine if you just wait [Read more] |
Darknight07 OFFLINE Forum Posts: 37 |
Posted: Tue, 18/04/2023 11:49 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Mon, 17/04/2023 14:39 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Mon, 17/04/2023 12:51 (1 Year ago) |
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Darknight07 OFFLINE Forum Posts: 37 |
Posted: Mon, 17/04/2023 12:10 (1 Year ago) |
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