化学交流区

xabi1111

oxygen is more electronegativity than sulphur ler,so electron will attract from sulphur to oxygen to archieve the octet rule mer???

dunwan2tellu

原帖由 xabi1111 于 21-5-2006 12:18 AM 发表
so all salt eh bec which have O4 1 is ate and O3 1 is ite,rite.thanks for ur answer,i'll revised f4 and f5 and will not ask such easy question again

但是 NO3(-) 却是 nitrate ion ... 并不是 nitrite (nitrite = NO2)

xabi1111

so the naming is base on the condition???

dunwan2tellu

原帖由 xabi1111 于 21-5-2006 12:29 AM 发表
so the naming is base on the condition???

算是吧。因为当他是 acid 时，却变成 sulphuric acid(H2SO4),而 HNO2 = acid nitrous .所以又没有明确的命名法我也不清楚。不像 organic compound 有 IUPAC 方法来取名。

kensai

SO3 的 画法我忘记了，要找回去年的 notes,

不过我记得 应该是 1 个 dative( O with -2 charge), 2 个double,

或者是 1 个 double, 2 个 single( Oxygen with -1 charge) , 0 dative

kensai

原帖由 dunwan2tellu 于 21-5-2006 12:18 AM 发表


是3个double bond 吧？  S = 0

SO3 是 2- charge 的，

a pure hydrocarbon was completely isolated from bottled gas used fot cooking and heating. when 10cm cube of the hydrocarbon were burned in 70cm cube of oxygen(an excess), the final gaseous mixture contained 30cm cube of carbon dioxide and 20cm cube of unreacted oxygen. allgaseous volumes were meansured under identical conditions. what is the fomula of the hydrocarbon?
can help me answer thx

[ 本帖最后由 ~ciyun~ 于 21-5-2006 12:40 AM 编辑 ]

kensai

原帖由 xabi1111 于 21-5-2006 12:29 AM 发表
so the naming is base on the condition???

本人建议naming 的 死背就行了，
常用的也只有这几个罢了，

organic 的话，就有 iupac 做参考。

还有不好意识，我不是说你foundation 不好，
是说 siyun,

xabi1111

diagram(connect by an external circuit)
left hand side--grey tin(electrode g)
right hand side---white tin(electrode w)
electrolyte--(NH4)2SNCL6 (aq)

white tin and grey tin are in equilibrium at 18degreeC
below 18degreeC,white tin dissolves from W and is deposited on G as grey tin

which of the following statesments are correct?
1.the stable form of tin at 25degreeC is grey
2.below 18degreeC,electrons flow through the external circuit from W to G
3.at 18degreeC,no current flows.

kensai

原帖由 ~ciyun~ 于 21-5-2006 12:38 AM 发表
a pure hydrocarbon was completely isolated from bottled gas used fot cooking and heating. when 10cm cube of the hydrocarbon were burned in 70cm cube of oxygen(an excess), the final gaseous mixture  ...

其实这些 stoichiometry 问题 用 CxHy + (x + y/4) O2 -> X CO2 + y/2 H20 的 formila 来找就可以了，
自己学习看看

dunwan2tellu

原帖由 kensai 于 21-5-2006 12:36 AM 发表



SO3 是 2- charge 的，

SO3 里，S 的 6 个 valens electron 都和 O 做 bond 了，有何来 2- charge ?

kensai

原帖由 xabi1111 于 21-5-2006 12:42 AM 发表
diagram(connect by an external circuit)
left hand side--grey tin(electrode g)
right hand side---white tin(electrode w)
electrolyte--(NH4)2SNCL6 (aq)

white tin and grey tin are in equilibrium  ...

这一题不是很决定，我很可能会错
1)temperature > 18, 应该white tin 会more stable
2) 对
3）不清楚

谢谢你的教导。我的英文不是很好再加上学笑还没开时教书。所以一些容易的我也不是怎磨会做的！稀望你能谅解。那请问你有网之可以学到化学的！谢谢

a question
since 1850,most books have been printed on acidic paper,which eventually becomes brittle and disintegrates. these books can be preserved by treament with diethylzinc vapour, ZN(C2H5)2,which reacts both with acid residues and also with small amounts of water retainted in the paper.
Diethylzinc reacts with an acid to give ethane.
Zn(C2H5)2+2HX-->ZnX2+2C2H6
which products are likely to result from the reaction of diethylzinc with water?

diethylzinc vapour malay call what?

kensai

原帖由 dunwan2tellu 于 21-5-2006 12:46 AM 发表


SO3 里，S 的 6 个 valens electron 都和 O 做 bond 了，有何来 2- charge ?

我是说3个 oxygen 里面，其中一个是 o2- ion,或者是 两个 oxygen 有-1 charge, 这个我忘记了，但我记得是其中一个

SO3 是 complex ion，然后overall charge 是 2-
不然 H2SO3, Na2SO3 这些 compound 怎样form 呢？

如果 so3 的 overall charge 是 0， 那他就不能form 上面那些ion 了

kensai

给我找到了，so3 2- 的 structure

http://www.brookscole.com/chemis ... ime/sulfiteion.html

kensai

原帖由 ~ciyun~ 于 21-5-2006 12:47 PM 发表
谢谢你的教导。我的英文不是很好再加上学笑还没开时教书。所以一些容易的我也不是怎磨会做的！稀望你能谅解。那请问你有网之可以学到化学的！谢谢

internet 那些通常只是用来满足那些课本满足不到他们的人，
大多数internet 里面的，有些太复杂，有些太简单，
我觉得最好的还是revise 以前 form 4, form 5 的 pelangi , fajar bakti 那些书更好，

kensai

原帖由 ~ciyun~ 于 21-5-2006 01:22 PM 发表
a question
since 1850,most books have been printed on acidic paper,which eventually becomes brittle and disintegrates. these books can be preserved by treament with diethylzinc vapour, ZN(C2H5)2,w ...

ZnO +2C2H6

xabi1111

answer is 1 and 2 wor

xabi1111

i dont,understand for y the statement no. 1 is correct ..


the SO3 eh structure i oso found d,but is
http://webbook.nist.gov/cgi/cbook.cgi?ID=C7446119&Units=SI