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标题: SPM Chemistry(化学）急急急～ Chemistry这俩题怎样做？ [打印本页]

作者: ArianaCullen 时间: 2013-4-14 09:51 AM
标题: SPM Chemistry(化学）急急急～ Chemistry这俩题怎样做？
各位SPM 化学大侠请救救我，我这俩题题目来自SPM Chemistry paper 3 section C，请帮帮忙，小女刚上中四什么都不适应，成绩一落千丈，不知如何是好

9. (a) Figure below shows the symbol representing an atom of sodium

                  nucleon no. : 23
                  proton no. : 11
                  symbol of element: Na

Based on the information given, elaborate the structure of sodium atom. your answer should include the diagram of electron arrangement and number of subatomic particles in the sodium atom. (4 marks)

(b) Organic compound X is a solid at room temperature and pressure. The melting point of X is less than 100°C.

(i) Describe a laboratory experiment to determine the freezing point of solid X. your answer should consist of following.

--> List of materials and apparatus required
--> Diagram showing the set-up of apparatus
--> Procedure of the experiment
--> Tabulation of data
--> Interpretation of data             (10 marks)

(ii) Describe the changes occurred in the arrangement of molecules, attractive forces between the molecules and the energy content of compound X when it is cooled from 100°C to room temperature. (6 marks)

10. (a) (i) What is a chemical formula? (1 mark)
         (ii) State the qualitative and quantitative information that a chemical equation can provide. (3 marks)

   (b) (i) Name a metal which is less reactive than hydrogen in the reactivity series. (1 mark)
         (ii) Describe a laboratory experiment to determine the empirical formula of the oxide of the metal named in (b)(i) above. (10 marks)

(c) Nowadays, most of the cars are equipped with airbags that sodium azide, NaN3. Sodium azide decomposes quickly when heated to produce nitrogen gas and sodium. The gas prodeced will expand the air bag.
Calculate the mass of sodium azide required to produce just enough nitrogen gas to inflate an air bag of volume 35 dm3 at room conditions. (relative atomic mass: N,14; Na, 23; Molar volume of gas at room conditions = 24 dm3 mol-1) (5 marks)

作者: kaze1231 时间: 2013-4-14 11:07 AM
这是中四第二课的吗？如果experiment的话多数参考书都有我chemistry也没很好

而且毕业两年了帮不上太多忙

作者: ~^Magician^~ 时间: 2013-4-14 11:08 AM
9. (a)

作者: xiao.zhu 时间: 2013-4-14 11:36 AM
9b Naphthalene
Naphthalene is an organic compound with formula C10H8.
Melting point
80.26 °C, 353 K, 176 °F
http://en.wikipedia.org/wiki/Naphthalene

作者: ArianaCullen 时间: 2013-4-14 11:59 AM
本帖最后由 ArianaCullen 于 2013-4-14 12:06 PM 编辑

kaze1231 发表于 2013-4-14 11:07 AM
这是中四第二课的吗？如果experiment的话多数参考书都有我chemistry也没很好而且毕业两年了帮不上太多 ...

嗯～是第二课～请救救我T.T

作者: ArianaCullen 时间: 2013-4-14 12:01 PM

~^Magician^~ 发表于 2013-4-14 11:08 AM
9. (a)

你还能再答吗？我真的不会，22我chemistry参考书念了还不会，上课又听不懂～

作者: ArianaCullen 时间: 2013-4-14 12:02 PM

xiao.zhu 发表于 2013-4-14 11:36 AM
9b Naphthalene
Naphthalene is an organic compound with formula C10H8.
Melting point

大侠还会吗？T.T 救命啊啊啊～

作者: xiao.zhu 时间: 2013-4-14 12:08 PM

ArianaCullen 发表于 2013-4-14 12:02 PM
大侠还会吗？T.T 救命啊啊啊～

http://books.google.com.my/books ... 20point&f=false

refer activity 2.2

page 47

作者: xiao.zhu 时间: 2013-4-14 12:10 PM
其实很多东西你google一下就有

作者: ArianaCullen 时间: 2013-4-14 12:19 PM

xiao.zhu 发表于 2013-4-14 12:10 PM
其实很多东西你google一下就有

真的非常非常谢谢你。。。

那第10题的是哪一个experiment的？

作者: 十五月亮十六圆 时间: 2013-4-14 01:02 PM

ArianaCullen 发表于 2013-4-14 12:01 PM
你还能再答吗？我真的不会，22我chemistry参考书念了还不会，上课又听不懂～

sodium : 2.8 .1 it has 2 electron valence in outermost shell ..It is belongs to Group 1 element .its proton number is 11

然后实验是Heating of naphthalene , 它的graph 是很像梯级的，需要的材料当然包括温度计，记录时间的，beaker , conical flask .......

chemical formulae 可以让我们知道多少product will be produced and how much the chemicals need to be prepared

作者: ♂☆小爱★♀ 时间: 2013-4-14 02:13 PM
参考书很多那种experiment的东西，改改一下就可以了

作者: 炎黄 时间: 2013-4-14 02:21 PM
[img]%5Burl=http://postimg.org/image/utuhclsxl/full/%5D

[/url] windows 7 screen shot[/img]
10c试做了一下，有错的话大侠们纠正吧

作者: =橙子= 时间: 2013-4-14 02:53 PM
本帖最后由 =橙子= 于 2013-4-14 05:02 PM 编辑

9. (a) Figure below shows the symbol representing an atom of sodium

                  nucleon no. : 23
                  proton no. : 11
                  symbol of element: Na

Based on the information given, elaborate the structure of sodium atom. your answer should include the diagram of electron arrangement and number of subatomic particles in the sodium atom. (4 marks)
-group 1 element
-diagram
-electronic configuration : 2.8.1
-valence number of electron: 1
-no. of proton = 11
-no. of electron =11
-no. of neutron =12

当然不是用简写写@@  还有不懂可不可以用point form

(b) Organic compound X is a solid at room temperature and pressure. The melting point of X is less than 100°C.

(i) Describe a laboratory experiment to determine the freezing point of solid X. your answer should consist of following.

--> List of materials and apparatus required
--> Diagram showing the set-up of apparatus
--> Procedure of the experiment
--> Tabulation of data
--> Interpretation of data             (10 marks)

这个参考书应该有
应该是naphthalene

(ii) Describe the changes occurred in the arrangement of molecules, attractive forces between the molecules and the energy content of compound X when it is cooled from 100°C to room temperature. (6 marks)
-就写 100°C 是 gas. arrangement of molecule 是什么， attractive forces
-room temperature 大概是27°C。他是solid, arrangement 好像是orderly manner,  attractive force

*大概是那样  我不是很记得了

10. (a) (i) What is a chemical formula? (1 mark) --> 课本有  （a formula shows  the total  no. of atom of each element in a compound  )(*应该是那样）

         (ii) State the qualitative and quantitative information that a chemical equation can provide. (3 marks)
      -忘记是什么

   (b) (i) Name a metal which is less reactive than hydrogen in the reactivity series. (1 mark)
更正**  是用cu or ag

         (ii) Describe a laboratory experiment to determine the empirical formula of the oxide of the metal named in (b)(i) above. (10 marks)
这个老师应该有教有一种是heat,另一种是用hydrogen gas pass through 的

(c) Nowadays, most of the cars are equipped with airbags that sodium azide, NaN3. Sodium azide decomposes quickly when heated to produce nitrogen gas and sodium. The gas prodeced will expand the air bag.
Calculate the mass of sodium azide required to produce just enough nitrogen gas to inflate an air bag of volume 35 dm3 at room conditions. (relative atomic mass: N,14; Na, 23; Molar volume of gas at room conditions = 24 dm3 mol-1) (5 marks)

先写Equation, balanced
然后找no. of mol
就可以做了

不好意思哦
我忘得7788了

作者: 谦.之语 时间: 2013-4-14 03:06 PM
楼主可以去问问老师，就可以settle，老师还可以解释清楚给你听

不过这些都是容易的题目，多做课本和练习就可以了~~

作者: lalazaza 时间: 2013-4-14 04:42 PM

=橙子= 发表于 2013-4-14 02:53 PM
9. (a) Figure below shows the symbol representing an atom of sodium

nucleon n ...

不好意思，我对楼上的答案有些疑问，我们可以一起讨论。

(b) (i) Name a metal which is less reactive than hydrogen in the reactivity series. (1 mark)
（Na , K) 是 very reactive 的.
Hydrogen 下的metal 都可以例如 copper, gold, silver.

(ii) Describe a laboratory experiment to determine the empirical formula of the oxide of the metal named in (b)(i) above. (10 marks)
楼主看参考书，多数给的例子是copper(II) oxide. 多是用hydrogen gas pass through 的。
重点包括 :
1. Hydrogen gas is allowed to flow for 5-10 minutes to remove all the air.
2. Excess hydrogen gas is burnt and copper (II) oxide is heated strongly.

作者: =橙子= 时间: 2013-4-14 04:58 PM
本帖最后由 =橙子= 于 2013-4-14 05:02 PM 编辑

lalazaza 发表于 2013-4-14 04:42 PM
不好意思，我对楼上的答案有些疑问，我们可以一起讨论。

(b) (i) Name a metal which is less reacti ...

因为我已经SPM毕业2年多了
所以我也不太记得

不过你说是对

我忽略了一点
忘记hydrogen 不是group 1
谢谢你的提醒

这题应该based on
K,Na, Ca, Mg, Al, Zn, Fe, Sn , Pb, H , Cu ,Ag

应该是拿后面两个

作者: 枇杷膏 时间: 2013-4-14 06:24 PM
3年前的我肯定可以帮你~哈哈哈哈~

作者: xianchua 时间: 2013-4-14 07:15 PM
虽然我spm chemistry 拿 A。。但我全都忘了

作者: xianchua 时间: 2013-4-14 07:16 PM
楼主没有去补习吗？

作者: freebitch 时间: 2013-4-14 08:27 PM
楼主你的chemistry 现在还在第二课你就好追上去了！！
想当初我的chemistry 到了CHEMICAL EQUATION 那里就不会了，而且后面都会有用到Equition ！
不过你还是可以逃过不会equition 的命运，就是那些equation你要背起来～

作者: ~贤_雨~ 时间: 2013-4-14 09:58 PM
好怀念阿

作者: 冬眠者 时间: 2013-4-14 11:05 PM
楼主，我可以教你theory，但不想直接写答案给你，因为这样是学不到东西的。

作者: XiaoL3i 时间: 2013-4-15 01:16 AM
其实这些题目我记得有做过的= = 楼主用心点吧

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