高中生高含金量计算机竞赛盘点！
在STEM专业申请难度水涨船高的趋势中，计算机专业始终是STEM中“热上加热”的专业，高就业率、高薪资是它的代名词。 对于喜欢计算机专业的留学预备党来说，参加高含金量计算机国际学术活动不仅可以提升计算机硬实力...
CIE A Level Chemistry复习笔记3.8.1 Addition Polymerisation
Addition Polymerisation: Polythene & PVC Addition polymerisation Addition polymerisation is one of the most important addition reactions of alkenes which form the basis of the plastic industry ...
CIE A Level Chemistry复习笔记3.7.2 Nitriles & Hydroxynitriles
Production of Nitriles Nitriles are compounds with a -CN functional group They can be prepared from the nucleophilic substitution of halogenoalkanes Propanenitrile, an example of a nitrile Reaction...
CIE A Level Chemistry复习笔记3.7.1 Primary Amines
Production of Amines Amines are compounds with the amine (-NH2) functional group They can be produced as a result of nucleophilic substitution reactions of halogenoalkanes when they are heated unde...
CIE A Level Chemistry复习笔记3.6.2 Esters
Production of Esters Esters are compounds with an -COOR functional group and are characterised by their sweet and fruity smells They are prepared from the condensation reaction between a carboxylic...
CIE A Level Chemistry复习笔记3.6.1 Carboxylic Acids
Production of Carboxylic Acids Carboxylic acids are compounds with a -COOH functional group They can be prepared by a series of different reactions Oxidation of primary alcohols & aldehydes Car...
CIE A Level Chemistry复习笔记3.5.5 Iodoform Reaction
Iodoform Reaction Tri-iodomethane (also called iodoform) forms a yellow precipitate with methyl ketones Methyl ketones are compounds that have a CH3CO-group Ethanal also contains a CH3CO- group and...
CIE A Level Chemistry复习笔记3.5.4 Carbonyl Compound Tests
Testing for Carbonyls: 2,4-DNPH 2,4-dinitrophenylhydrazine (also known as 2,4-DNPH) is a reagent which detects the presence of carbonyl compounds (compounds with -C=O group) The carbonyl group of a...
CIE A Level Chemistry复习笔记3.5.3 Reaction with HCN
Reaction of Hydrogen Cyanide with Aldehydes & Ketones The carbonyl group -C=O, in aldehydes and ketones is polarised The oxygen atom is more electronegative than carbon drawing electron density...
