2011 GCE O Level Chemistry P2 (Pure) Suggested Solutions

烈帝～ · 发表于 2-11-2011 06:25:36|来自：新加坡

无奈的我啊发表于 1-11-2011 23:46
A7(c) 应该是UO2吧。因为是Uranium(IV) 老师把IV看成V了吧！反正多谢答案！

郁闷我也看错

烈帝～ · 发表于 2-11-2011 06:27:20|来自：新加坡

冷风1985 发表于 2-11-2011 01:09
Chlorine gas is not compound, because there is only one kind of element in the molecule Cl2. Such m ...

多谢
可能想太多了因为potassium chloride是离子形式出现的所以以为没有结合...

逍遥在世 · 发表于 2-11-2011 08:50:55|来自：新加坡

谢谢老师的答案

lwonderful · 发表于 2-11-2011 09:45:17|来自：新加坡

老师 question 5 （ iV） the mole ration for the equation is 2: 5:4: 2 , 有两个mole de C2H2 他的 200000kj 不是应该再除以2吗？

JamesKhoo · 发表于 2-11-2011 09:45:48|来自：新加坡

For 2d can we say that the cathode produces both oxygen and water?
6aii Possible to talk about the difference in viscosity?
6c Can I say that hexene and cycloheptane have the same general formula of CxH2x but hexane has a general formula of CxH(2x+2)
6cii Can I say that transition metals are coloured compunds and since metals form basic oxides, it is thus a basic oxide?

And if the question does not state the need for state symbols and if i dont write them its fine right? And for question 9cii if the answer is supposed to be 1.625 tonnes and i round it off to 1.63 tonnes..?

云海儿 · 发表于 2-11-2011 10:38:32|来自：新加坡

qwe561187 发表于 2-11-2011 10:25
请问4b是否有必要提到large amount of energy is required to break the covalent bond??? 因为我题目问的 ...

我也是跟你一样写的。:x

我大概是损失了8-9分吧, 到底A1还有没有啊。。。>,<

冷风1985 · 发表于 2-11-2011 12:42:37|来自：新加坡

本帖最后由冷风1985 于 13-11-2011 15:54 编辑

qwe561187 发表于 2-11-2011 10:25
请问4b是否有必要提到large amount of energy is required to break the covalent bond??? 因为我题目问的 ...

you don't need to mention large energy is required to break the covalent bond. But at least you need to state that the bonds are very strong.
Tetrahedral Structure has nothing to do with Strong. For example: CH4, is gas.

Ps: students tends to misunderstand the term "energy is required" as "thermal enerty is required".
Actually, energy includes a lot of types: kinetic, thermal, potential, chemical, solar, etc...