[DSE化學2018]同學準備好DSE CHEM未? (2)

加油 AL年代好佩服d文科frd作文寫足十幾板 要加薄 唔係加紙

無話一定唔得既 tin plating係傳統方法同平啫

joint us本書 dse sample paper ans用呢個
果條用唔到第2個reagent做?

可以咁樣掉轉dehydration? 定係我溫少左呢個reaction

呢個reaction out syl的 叫catalytic hydration
CE野黎 正常用dilute H2SO4 or H3PO4做catalyst
但唔熟無謂亂用 佢出得題都唔會要你用到呢d extra既反應

joint us本書 dse sample paper ans用呢個
果條用唔到第2個reagent做?

咪加HBr 先
再加NaOH sub 咗個Br

thanks

yes

同問

其實寧願上黎問
都唔肯打開本textbook / google 係咩心態

咁好多時學科知識同考試要求係有落差既
如果問你what is acid 你google起碼查到3個definition 而又無一個係100% fit DSE既定義

而且好老實教科書都唔係所有野都啱
例如你返去睇下自己本textbook教你alkaline hydrolysis of ester/amide個NaOH係咪catalyst

not catalyst
但我睇過有本textbook仲係寫catalyst
24 hrs果本都係

咁我delete 返我句google

其實都冇需要討論啦
學生有問題問又有人答絕對係好事

自己都係過來人 都係純粹唔想大家盲人摸象讀得咁辛苦啫

exact marking: A standard solution of the substance can be prepared by dissolving a known mass of the substance in a solvent and making up the solution to a known volume.

reference: AL 2007 P1 Q7(c)

Primary standard係指可以直接開standard solution既substances
計好用幾多mass primary standard-> dissolve in known volume of solvent -> standard solution

complex out syl wor師兄