[2022DSE CHEM化學］問答討論區

好驚，之前數學收咗皮。希望chem 可以攞返個4

H-N/O/F 其實都唔係一個準確講法，重點係嗰H (H-bond acceptor) 要highly exposed with a relative high delta +ve charge，而H-bond donor係lone pairs on highly electronegative atoms (mostly to be F/N/O

例如，trichloromethane 同 acetone之間，係有hydrogen bond的。
3 chlorine atoms in trichloromethane draw electrons towards themselves, which results in a relatively highly +ve charge on the hydrogen atom. It forms a hydrogen bond with lone pairs on oxygen atom in acetone

chloroform同acetone呢個應該係佢地唯一學嘅exceptional case

祝各位順順利利

2個 cases 仲叫唔叫唯一

雖然聽日要考chem嘅而家都應該瞓咗教
但係都同你哋講聲加油

佢講緊chloroform同acetone mix埋一齊嘅呢一個case

各自兩隻野自己係無H bond
係mix埋一齊先有 咁咪呢一個case

Yes. 重點係本身各自冇，但mix埋一齊會有，而且過程會放熱exothermic (A-B interaction is stronger than A-A and B-B interaction).

題外話，呢d mixture叫 negative azeotrope (A-B > A-A or A+B)

師兄係咪讀Chem
啲Term都係大學Chem先知

唔係呀，我degree係Biochemistry，畢業多年了。A-level後嘅chemistry 係自己學返黎。

paper 1 淺到

啲數唔易計感覺lower quartile 條curve會低咗

今年都少咗好多分5,5*,5**題目，得用mgoh2嘅好處嗰條可能難啲，今年如果想攞*要比平時更加小心

有邊條難

感覺計standard enthalpy change of neutralization有好多人會唔記得除返2

今年條Curve會唔會仲高過舊年

考評局算好人題目一開頭已經講明

我估應該唔會
雖然係簡單但條curve唔會高得去邊 因為點都有啲位學生係會錯
同埋上年已經係好高

加上要睇埋p2咩難度

易到傻，有個幾鐘check
好後悔冇中途去廁所

唔難啦，我記得幾年前做MC嗰本練習
呢條題目得兩粒辣椒

題目都提埋係 每mole water
平時點會有呢句

係，係我就唔比

真 完全估唔到會提埋