回答|共 34 个

本小姐_依琳 LV3

发表于 2-11-2011 19:47:19 | 显示全部楼层

Qn8b(i) can it be silicon(IV) oxide?
Qn9a can the answer be marble?
Qn10a(i) must i write the solution changes from what colour to what colour?

点评

8b silicon (IV) oxide is acceptable. 9a Marble is also acceptable. 10a must tell the color change.  详情 回复 发表于 13-11-2011 15:51

SNSDJess LV1

发表于 2-11-2011 22:35:35 | 显示全部楼层

小狮租房
May i know whats the minimum mark you should be getting for this paper to consider for a A1?
For qn2d, if i never compare will i get 0? I only say that it will produce H2 at cathode and O2 at anode.
For qn 6c, can i talk about the molecular formula? hexene and cycloheptane have same molecular formula but they have different from hexane.?
And SiO2 can i name it Silicon(IV) oxide?

Please answer my question. Thank you for your hard work! ;D

点评

2d I am afraid you can only get half of the marks. 6c Hexene and cycloheptane have different molecular formula. They have same empirical formula. Silicon (IV) oxide is ok  详情 回复 发表于 13-11-2011 15:41

taxy LV5

发表于 3-11-2011 01:37:15 | 显示全部楼层

老师你好,有几个问题想问问我这样写能得分不,大家谁有空也帮我看看谢谢
2(a)(ii)compound only consists of one kind molecule but mixture consists of atoms or molecules
c(ii)apply damp blue litmus paper into the gas if it is bleached ,the gas is chlorine
(iii)H2so4 ionise more hydrogen ions in soultion ,hence the concerntration of H+ ions will increase which increase the rate of reaction
3(c)(ii)calcium carbonate reacts with surfuric acid to form a layer on the surface of calcium carbonate ,which prevent beneath caclium carbonate reacting

4(a)Diamond has giant covalent structure ,the force of attrctions bettwen atoms is very strong ,hence ot is hard
6(a)they have common formular

(c)hexene and cyclohepatne have the common morlecular formula CnH2n hence percentage of carbon of them will be differnt from hexane ,which is alkane,has molecular formula CnH2n+2

10(a)addition polymers are formed by monomers join together to produce only one molecule but condensation polymers are formed by monomers join together by emmiting small molecules

点评

10 (a) will be accepted.  详情 回复 发表于 13-11-2011 15:32
6(a) is wrong. Should be same "General Formula". 6(c) is wrong. Should be "empirical formula". Reason: CH4, C2H6 same general formula, bu   详情 回复 发表于 13-11-2011 15:31
3(c) is correct. 4 (a) is wrong. The question asked you to compare "giant molecular structure" and "simple Molecular Structure", while in your answer, you never do any comparison.   详情 回复 发表于 13-11-2011 15:24
2c (ii) (iii) both are correct  详情 回复 发表于 13-11-2011 15:17
2 (a) compound only consists of one kind of molecule, 这个说法不是很对, 因为有些compound里面是没有molecule的, 比如说所有ionic structure的物质, 诸如NaCl,  详情 回复 发表于 13-11-2011 15:15

邱勃翰 LV4

发表于 17-11-2011 18:13:01 | 显示全部楼层

哎呦!不错哦 我还没考o level 明年考 学哥学姐有什么好的办法能学好o level 呢??帮帮老弟了 谢谢!!!
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