AL Chemistry Discussion

kawai

Originally posted by 納比 at 2005-3-18 05:12 PM:
ｘ．．．Lewis acid 乜野黎的．．．

同bronsted-lowry acid既定義完全相反
聞說完全掌握的的話
inorg可以一條式都唔法背

kawai

Originally posted by kawai at 2005-3-18 06:32 PM:

同bronsted-lowry acid既定義完全相反
聞說完全掌握的的話
inorg可以一條式都唔法背

但係out c

Newcastle Fans

Originally posted by kawai at 2005-3-18 18:32:
聞說完全掌握的的話
inorg可以一條式都唔法背

我寧願背

kawai

Originally posted by Newcastle Fans at 2005-3-18 06:39 PM:

我寧願背

事實上唔係難野
但係點樣將佢同條式融會貫通先係最難

MZN

Originally posted by Newcastle Fans at 2005-3-18 01:10 PM:
有個大問題... help!
2003年Paper II
No.7(b)(iii)
係問點樣將benzene變做diphenylmethane... (一個carbon連住兩個H同埋兩個benzene ring)
marking scheme就用左3個step...
佢隔離就寫左D野... 係用一個ste ...

actually AlCl3 and FeCl3 are the same
主要都係想整e條野出黎

FeCl3 + R-Cl <----> FeCl4 - + R+
AlCl3 + R-Cl <-----> AlCl4 - + R+

唔知arm唔arm~

nichart

我想問下關於cell diagram的

93 paper 2

咁marking 話

Cathode:Pb02(s)+ 4H+(aq) + SO4^2-(aq) + 2e- > PbSO4(s) + 2H2O(l)

Anode:Pb(s) + SO4^2-(aq) > PbSO4(s) + 2e-

Cell diagram:
Pb(s)|PbSO4(s)|PbO2(s)|H2SO4(aq)|PbSO4(s)|Pb(s)

點解可以skip左anode既SO4^2- and cathode 既H2O?乜唔係要寫晒既咩?

仲有寫anode/cathode既component 係未唔駛順序寫(即係由reactant side到product)，我見marking有時就掉轉左

THX

stephenlion

又有稀客
welcome back

kawai

Originally posted by nichart at 2005-3-26 10:29 PM:
我想問下關於cell diagram的

93 paper 2

咁marking 話

Cathode:Pb02(s)+ 4H+(aq) + SO4^2-(aq) + 2e- > PbSO4(s) + 2H2O(l)

Anode:Pb(s) + SO4^2-(aq) > PbSO4(s) + 2e-

Cell diagram:
Pb ...

望下98年II 4 o既marking
應該幫到你

Newcastle Fans

我想問下... 最少有幾多先secure到一個B... 65%?

Newcastle Fans

仲有一個問題...
如果我地有個咁既reaction
A + B ------> C + D
我地有[A] at diffient time
咁我地要prove個reaction w.r.t. [A] 係1st order
我地畫呢個graph: ln[A] Vs time
有straight line就得

咁我地可唔可以畫呢個呢?
ln ( [A]initial / [A] ) Vs time
會有一條straight line passing through origin
得唔得呢?
隔離班就用得
但我地班阿sir冇講過
marking scheme亦冇用過呢條
但一樣prove到, 一樣計到rate constant

bobby_zamora

Originally posted by Newcastle Fans at 2005-3-28 05:51 PM:
我想問下... 最少有幾多先secure到一個B... 65%?

>65 gwa

Tung

我覺得咁多年past paper....99好X難

MZN

Originally posted by Newcastle Fans at 2005-3-28 06:22 PM:
仲有一個問題...
如果我地有個咁既reaction
A + B ------> C + D
我地有[A] at diffient time
咁我地要prove個reaction w.r.t. [A] 係1st order
我地畫呢個graph: ln[A] Vs time
有straight line就得
...

根本一樣...
ln[A ini.] 係一個const.