[DSE化學2018]同學準備好DSE CHEM未?

化學艾維斯 · 2017-08-25T22:29:35+08:00

之前2016 2017 DSE都有開同名post 不過果時忙都係考前一個月先開今年quit左補習社恢復自由身少左d限制又得閒d 今年就早d開post 等多d學生睇到循例講下自己背景先小弟之前做開補習社CHEM老師全職專教左超過六年DSE CHEM 三大CHEM major grad 報考過2013-2017 DSE CHEM 五屆全5** (2012無報考) 全香港暫時得我一個傻佬考左咁多次5**返黎 (睇HKEA年報) 唔敢話勁過其他補習老師但自問都叫做有d研究有小小心得可以分享下呢個post主要係for 2018 DSE同學問問題有d咩關於DSE CHEM既問題都可以問，我會儘量解答不過都係果句，太out syl果d野就最好唔好，好易愈溫愈亂，考試大忌我亦都會不定時upload唔同既material比大家，例如試題分析，精讀notes等等如果有chem問題要聯絡我 / 提供意見，都可以telegram我：elvislamchem 今年有樣新野，就係我自己開左個youtube channel "5** Chemistry" https://www.youtube.com/channel/UCPE9pbWdjviOfSWRn9V2kRQ 會一路拍片同大家分享下點應付DSE CHEM 暫時拍緊DSE題目既詳解依家拍緊2017 chem 之後會多d唔同主題例如分析下歷屆exam report / 出題分佈 / 唔同題型既做法 / elective貼題...等等睇過覺得好既請like / subscribe 有咩意見覺得有咩地方要改善有咩想我拍片都歡迎同我講最後講多樣今年離開左補習社就係覺得有太多地方唔乎合自己理念補習收人錢天經地義但都要真係教到人真正令學生有得著所以我想比d時間自己試下攪掂既當然好無人認同既都當了左個心願依家我暫時做緊chem私補/小組補，都有d學生睇下呢個post反應如何如果多同學有興趣黎緊開學可能試下租個課室幫大家補下底 / 追星

化學艾維斯

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魏娘 2017-12-29 23:10:26

你講chemical cell果個?定cracking
Cracking果個原因真係查唔到
但chemical cell果隻又係咩？

cracking果個係catalyst 主要成分有Al2O3
mechanism上令carbon chain上既H抽走左形成cation 進而令條chain rearrange而斷開

chemical cell果個純粹係有small hole容許ion有限度地通過 maintain the overall charge balance between two half cells (prevent internal resistance build up)
chemical cell 係咪得industrial chem嘅diaphragm cell 先係

Hydrogen-oxygen fuel cell 個nickel electrode 都係porous
仲有一個唔洗點識嘅daniell cell 都係

化學艾維斯 2017-12-30 02:51:54

cell個porous pot係allow ion pass through
作為salt bridge咁用

fuel cell既electrode整成porous係為左increase surface area so that increase the catalytic efficiency

化學艾維斯 2017-12-30 02:53:38

睇electrolyte用acid定alkali
H2 fuel cell alkaline cell黎

化學艾維斯 2017-12-30 13:48:30

technically speaking cracking to form hydrogen and carbon (especially under high temperature condition)
usually they are considered as side products (carbon will be burnt off) and we do not intend to obtain them from cracking process
http://www.essentialchemicalindustry.org/processes/cracking-isomerisation-and-reforming.html

化學艾維斯 2017-12-30 13:49:18

technically speaking cracking do form hydrogen and carbon (especially under high temperature condition)
usually they are considered as side products (carbon will be burnt off) and we do not intend to obtain them from cracking process
http://www.essentialchemicalindustry.org/processes/cracking-isomerisation-and-reforming.html

化學艾維斯 2017-12-30 15:39:29

public exam考cracking基本會focus on hydrocarbon products only
出版社exercise我建議做下清下concept無問題
但唔洗強求個分數因為無乜邊間出既mock真係好貼近實際考試一係就太離地中學根本唔會識

我建議係得返3個月儘量做多d pastpaper (Ce/AL/DSE)去摸熟個問法同答法

化學艾維斯 2017-12-30 15:45:17

唔太關事有d mock根本個出法同難度都唔似公開試
另外呢其實chem唔應該用mc做指標
因為mc同lq係同一份卷 mc佔36分 lq 84分
答啱多題lq已經等於兩三題mc

之前我有學生試過mc 36題全中但出黎得lv 5

魏娘 2017-12-30 18:52:41