我們在準備IGCSE化學考試過程中，知識點的掌握是基礎，也是最重要的一部分。為了幫助同學們做好化學復習工作，A加未來小編就為大家整理了Paper2部分的一些重要的IGCSE化學考點，知識點還不夠扎實的同學們可以借此機會做好查漏補缺的工作。
這些是考試重點內容：
atomic structure
reactivity of metals
chemical test
organic
acid base and salt
calculation
energy change
bond energy
chromatography
elements,compounds and mixtures
the periodic table
rate of reaction
electrolysis
redox
equilibrium
gas in atmosphere
group 7
state of matter
group 1
titration
dot and cross digram
bonding and structure
crude oil
ammonia
formula equation
group 2
alkene
今天，我主要來說說chemical test部分。按照大綱要求：
?。?）describe tests for these gases:
?hydrogen【‘pops’with a lighted splint】
?oxygen【relights a glowing splint】
?carbon dioxide【gives a white ppt.with limewater】
?ammonia【turns damp red litmus paper blue】
?chlorine【bleaches damp litmus paper】
?。?）describe how to carry out a flame test
【1.The technique is first of all to clean the end of a piece of platinum or nichrome wire by dipping it into clean hydrochloric acid and then placing it in a roaring Bunsen flame.This procedure should be repeated until the wire no longer produces a colour in the flame.
2.The end of the wire should then be dipped into fresh hydrochloric acid and then into the solid sample under test.
3.The end of the wire should then be placed into a non-roaring,non-luminous Bunsen flame.】
?。?）know the colours formed in flame tests for these cations:
?Li+is red
?Na+is yellow
?K+is lilac
?Ca2+is orange-red
?Cu2+is blue-green
?。?）test of cations
?NH4+using sodium hydroxide solution and identifying the gas evolved【放出的氣體是NH3】
?Cu2+,Fe2+and Fe3+using sodium hydroxide solution【Cu(OH)2,Fe(OH)2,Fe(OH)3顏色分別是blue,green,red-brown】
?。?）test of anions
?Cl–,Br–and I–using acidified silver nitrate solution【AgCl,AgBr,AgI顏色分別是white,cream,yellow】
?SO42–using acidified barium chloride solution【BaSO4是white precipitate】
?CO32–using hydrochloric acid and identifying the gas evolved.【CO2 is released】
來，我們看道真題：
解析：b題，含有SO42-離子的檢驗，那使用含有Ba2+離子的物質檢驗，答案選擇【solution of barium chloride】,觀察到白色沉淀BaSO4,因此答案是【white precipitate】。
C問，flame test中是lilac顏色的metal ion是K，答案選擇potassium.
怎么樣，對于這部分的IGCSE化學考點你是不是已經(jīng)深刻的掌握了呢？如果在學習過程中還有什么疑問，歡迎隨時咨詢我們的在線老師，讓老師一對一為你進行專業(yè)的課程學習輔導吧！
