DSE Chem 2019 你問我試吓重識唔識答
關愛座hunter
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各位加油
自製啲equation list
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方便last minute 求個安心
各位加油
自製啲equation list
Redox rxn list
Org Chem Ron list
Colour change list
方便last minute 求個安心
關蛇
Level 5題目
Salt bridge有乜用
Emulsification 嘅process係點
Ziegler Natta Catalyst 嘅用途
Molar Mass嘅definition 係乜
Salt bridge有乜用
Emulsification 嘅process係點
Ziegler Natta Catalyst 嘅用途
Molar Mass嘅definition 係乜
Level 5題目
Salt bridge有乜用
Emulsification 嘅process係點
Ziegler Natta Catalyst 嘅用途
Atomic Mass嘅definition 係乜
我地撐你呀！
咁都有lv5
利伸chem grad
利伸chem grad
salt bridge
喺兩個chemical half cell之間connect, 去complete一個circuit
最重要, salt bridge 上嘅ionic electrolyte, compensate 兩邊half cell cation 同anion, 令個cell run得耐啲
[model answer: to complete circuit; to provide electrolyte to balance charge on both half cell]
emulsification
1. detergents have wetting and emulsifying properties. Each detergent molecule contains a hydrophilic head and a hydrophobic tail.
2. like dissolves like. hydrophobic (oil-like) layer repels hydrophilic (water-like) layer [水嘅hydrogen bond太強, 油層嘅弱van der Waal's force打唔入]
3. wetting refers to ability of reduction of surface tension of interface [所謂surface tension微觀睇就係水嘅hydrogen bond做成嘅attractive force]
4. emulsifying refers to ability of breaking large grease into small oil droplets. This oil droplets can be stabilized by detergent molecule coating where hydrophilic head faces to water phase while hydrophobic tail inserts towards centre of oil droplets.
Ziegler Natta Catalyst
Catalysation of addition polymerization by reducing the activation energy, which is used to breaking the C=C bond, by coordination of C=C bond of monomers to the transition metal centre of the catalyst. 唔知會唔會答得太詳細
Molar mass
mass of one mole (6.02*10^23) of chemical formula of a substance, in g/mol
喺兩個chemical half cell之間connect, 去complete一個circuit
最重要, salt bridge 上嘅ionic electrolyte, compensate 兩邊half cell cation 同anion, 令個cell run得耐啲
[model answer: to complete circuit; to provide electrolyte to balance charge on both half cell]
emulsification
1. detergents have wetting and emulsifying properties. Each detergent molecule contains a hydrophilic head and a hydrophobic tail.
2. like dissolves like. hydrophobic (oil-like) layer repels hydrophilic (water-like) layer [水嘅hydrogen bond太強, 油層嘅弱van der Waal's force打唔入]
3. wetting refers to ability of reduction of surface tension of interface [所謂surface tension微觀睇就係水嘅hydrogen bond做成嘅attractive force]
4. emulsifying refers to ability of breaking large grease into small oil droplets. This oil droplets can be stabilized by detergent molecule coating where hydrophilic head faces to water phase while hydrophobic tail inserts towards centre of oil droplets.
Ziegler Natta Catalyst
Catalysation of addition polymerization by reducing the activation energy, which is used to breaking the C=C bond, by coordination of C=C bond of monomers to the transition metal centre of the catalyst. 唔知會唔會答得太詳細
Molar mass
mass of one mole (6.02*10^23) of chemical formula of a substance, in g/mol
以前: from nature嘅carbon compound
現在: 有exception: CO2, H2CO3都係from nature嘅carbon compound, 但為咗方便research study都當係inorganic.
而好多synthetic嘅compound都當係organic例如CFCs
現在: 有exception: CO2, H2CO3都係from nature嘅carbon compound, 但為咗方便research study都當係inorganic.
而好多synthetic嘅compound都當係organic例如CFCs
其實有bug, CH4秒殺你
冇catenation冇functional group
冇catenation冇functional group
Ziegler Natta Catalyst
Catalysation of addition polymerization by reducing the activation energy, which is used to breaking the C=C bond, by coordination of C=C bond of monomers to the transition metal centre of the catalyst. 唔知會唔會答得太詳細
catalyst個metal centre幫到手更易break C=C bond
Catalysation of addition polymerization by reducing the activation energy, which is used to breaking the C=C bond, by coordination of C=C bond of monomers to the transition metal centre of the catalyst. 唔知會唔會答得太詳細
catalyst個metal centre幫到手更易break C=C bond
industrial chem可能有提
不過可能唔使答咁深
不過可能唔使答咁深
atomic mass
想問relative atomic mass定relative isotopic mass?
想問relative atomic mass定relative isotopic mass?
Enthalpy change同molar mass/molar volume/molar concentration/density嘅數千篇一律
初中比例加減概念，千祈唔好錯過
初中比例加減概念，千祈唔好錯過
係，material chem比較深
我ALevel年代
CUHK Chem BSc grad
我ALevel年代
CUHK Chem BSc grad
係
Provide another pathway with reduced Ea
我錯
Provide another pathway with reduced Ea
我錯
大陸化學科係咪都係讀呢啲？
磚吓先
1 )Explain why trans isomers generally have a higher melting point than cis isomer
2) What can be observed at the end point of Mohr method? Write the chemical equation(s) which lead(s) to this observation.
3) Explain why blow torch is not suitable for drying Cu powder.
1 )Explain why trans isomers generally have a higher melting point than cis isomer
2) What can be observed at the end point of Mohr method? Write the chemical equation(s) which lead(s) to this observation.
3) Explain why blow torch is not suitable for drying Cu powder.