真四第張五第日十二月二十年寅甲插夏
育教
華僑華
中學會考專欄
|化學科
陳湛杰
CHEMISTRY
(#12)
WAH KIU YAT PO
weight of a third Bement, one
relative proportion by waight is in' a simple ratio to those which they (combine with one another.
Dalton's atómiò Theory, assumed that the atoms of elements were indivisible and that no particles smaller than atoms existed. Howeven as time passad, new, experimental faots led to modification, refine- ments and extensions..
One signifi-
cant finding was that atoms are
found to be composed of "fundamenta
particles" including protonė, t neutrone and electrons,
Thua atoms
報日懦
current by ions; 4.6. The Perodic table. Study your notes and text
book before attempting the question
Multiple Choice Questions
1. In the following regations,. one that is not an oxidation-. raduation réaction is (日). BaO2+H_304
S. BaSO4 + H2O2
(b) Za+il,504 = ZnSO4+H2
(c) 2HI = Hp+Ta
(d) C+HO = 00
(e) Zn+CuSO4 = Zn30g+Cu
2. For the equation:
日
solutions for Chemistry(#11)
Multiple Choice Questiona
|1(b): || 2(a) (- 3(6) · · 4(a) · ·|-5{c}
Conventional Questions
1: Delton's Atomic Theory was an fattempt to use the conoept of atoms
having fixed properties in in- terpreting the experimental laws of ohemical combination. It may be. summarized as follows:-
::
1. Elements are composed of indi- visible particles called atoma. Atoma retain their identity through all chemical changes. 2. Atoms of a particular element have the same average mass, and their other properties are also the
Atoms of different. elements generally have different average masses and different. properties.
3. Compounds are fumed by_com~
binations of the atom of differ- ent elements.
4. Atome of two or more elements
may combine in more than one ratio to for more than one compound...
AB
Law of Conservation of Mass – The indestrutibility of atome explains why all matter obeys this law, chemical changes produce only a rearrangement of atom in va
various combira tions, the total mass of the material involved in the transfor mations must: remain
of
Constant on
Compounds are formed by the com bination of definite number of different: atomay and given that eaoh.
atoma has a character, the relative weights.
the
dompound must
type
istic
of
[always be
be the same Taw of Multiple Proportions - The ability cof one atom of an element
to combine with one atom of another element to form a compound, or with "two or more atoms to form other. compounds, explains this observed
Jaw.
Jaw of. Equivalent (Reciprocal) Froportions The atomic theory leads to the idea that each element has a definite combining weight or equivalent, and when elements com- bine they do as in eiaple multiples of these quantities. This is in support to the fact that when two- elements each combing
女還停在外
方染介 伏圖及辣 狸解預
圣约
with a given
are really not the "ultimate" con- stituents of matter.
Furthermore,
the congept of conservation of matter and conservation of ener are replaced by the nor
Doncept of mass-energy equivalene - Lie, mase and energy are interwornvertible
under apecified conditioner Howeven due to the relatively low energy. changes during. chemical: reactione the
borresponding mass changes are extremely small.
2. Then oxalic acid crystals are beated with concentrated sulphuric acid, they are dehydrated to yield a mixture of carbon monoxide, and carbon dioxide.
H02042H20-3H10 →→ cop + 00 ↑ Thus 1 g molecule of oxalic acid provides 1 gm molecule of carbon monoxide and 1 g molecule of carbon-ddoxide.
According to Avogadro's hypothese equal numbers of different molecules of as accupy the same volume under the same physical conditions. Hence 1 g molecule of oxalic acid provides 2 molecules of gas. Molecular weight of oxalic acid crystals
_=2(1)+2(12)+4(16)+2(2416) = 136- Number of gm. molecules of oxalio Bàid
• បន
136
Number of go. molecules of gas generated =
As gram molecular volume for a gas at NTP conditions in 22.4 litres, thue volume of gas evolved at NIP conditions
x 22.4 litres
=
Jeing the gas equation
constant
at 100°C (373°K) and 800 mag of Hg pressure, volume of gaa
.
136 x 22.4 x
= 427.6co
潠
litres
When the gas mixture is allowed to atand over, caustic potash, narba. doxide is absorbed, leaving carbon monoxide. As indicated previously,
the mixture ie equinolar, con- taining equal volumes of the two
Therefore volume of remain- ing gas at NTF ia
22.4 litres
=16470c
Questions for Next Week.
The questions in this issue are
related to 4.4 Chemical equations;
4-5 The conduation of
加药、採可 帮而膏 商基”
:改善助
問。
electric.
-803 +
Br2+
__80 + Br
H
In order to balangs the above equation, the
the orders are should be in
221222 (b) 222244 (c) 211222- (a) 111122 e) 111112
3. If a current of 4 amperes is
passed through an electrolyte for two-thirds of an hour and given that one Faraday is 96,000 ounlosbe. what is the volume of oxygen that will be liberated at NIP con ditions? A
(a) 2800 (0) 550 mm
(e) 2:240cc
(b) 5.6 litres
(a) 22.4 litree.
4. The following are the electronic donfiguration of certain elementa 2.1 U. 2,4 V. 2,7 W. 2,8,2 I. 2,8,3 Y. 2,8,8. 2. 2,8,8,1
those Among the seven elements, that are non metals are; (a) T,U, V (b) 2,U,V,X
(e) nomè (c) W,X,Z(A) 7,21
5. For the same elemente as indi-
cated in 4, the elements that exist as gases at ordinary con dition are:-
(a). Tonly.
(a) v,x,z
(b)
W
Conventional questions.
1. State Farady's laws of electroly
A steady current of electricity was passed through two voltameters in series containing respectively:
copper sulphate solution and tap water. After some time,
the cathode of the former was
was dried and weighed, the incr
norease in weight was found to be 0.062gm. At the anode
the latter 11.7cc of evolved. The experiment was carrid cut at
at 1500 and atmospheric pressur What is the equivalent of copper as found. from this experiment?
gas Wis
2. What is the basis for the arm ringement, of the elements in the / modern periodic tables? Explain the following teins and illustrate with specific examples:
series (or period) (b) group.
(e) sub-group (d) transition elemente (e) typical elemente (f) first tianaition seriee (g) triads (h) family.
L975
科目
七月一日
中級海記
高級會計
中级成本會活
中學會考專業
The time, t, is unrectly prot
五期星
日一卅月一年五七九一层公年四十六國民中育教儒
mae
portional to the apecific latent
物理科 +
A
=2(150) (330 - 30)
· 300 x 300
300 09
T(e)
PHYSICS (12
Solutions
MIXTURE
Mepa Specific ht, capacity Temperature 100°C Final
metal water vessel p.1kg0.12kg0.03kg
14.2K
C
0
.16°C
16°C
Temperature 2800 2890 Temperature 72dez 12deg C Change (drop) (rise} Heat Joat 0.1x720 Heat gained
28°C
12deg C {rias).
Q.
42x12x12 0,03x12)
lleat lost - Heat gained
(1) Neglecting the specific hast
capacity of the vessel, 0.1 x 720 42. x 12 x 12 42 x 12 x12
C
0.1 72
840 在这
(ii) Taking the sp.ht. of the vessel into account, 0.1x720 42x12x12+0,03x120 (7.2-0.36)042 x 12 x 12. 42 x 12 x 12 16.84
886 K
(b) Heat taken from water to
vaporize one gramme of ammonia
= 1344 Ka
Heat: taken to freeze one gramme of water = 336 KT Taking 1344 XJ from water turne
1344. of water into los.
1344
336
钴 + =
To vaporize 15 kg of ammonia, it takea
1344 x 15 x 103 20.16 x 10 Kj This amount of energy i日 supplied in 5 mimites, Rate of heat-supply_
20-16 x 18
- 4032 x 10 kJ/min Time taken to freeze 600 kg of water.
600 x 103
x336
4032 x 102
= 50 minutes:
min
(e)(1) Hest required to bring the
bullet just to ita melting point,
Q = mc@
where m is the mass of bullet"
c, its specific beat
capacity
, its temperature rise (150)(330-30)
Q =mce.
=
Kinetic energy of bullet -Any2;
and via the velocity of the bullet. When it is brought to rest all
its kinetic energy
is
converted
into,heat
(11) Heat required to melt the :bullet
mcmi
(where I is the specific latent
heat of lead)
Kinetic energy of bullet dmv-
- mo8+ mL
2(150 x 300 + 25000)
= 2 x 70000 100/18
374 B
(111) When a lump of lead falle freely for 100m, its potential energy, pasta.
mg A x = 100 x 10m3
This produces heat of nee J
#. 0001 = 8OW
e
.1000.
=
哦
The temperature rise is 6
吧
(v):In melting this lump of lead heat required mo+mikw
= m(150x300+25000) -70000m J. Potential energy lost in free falling & distance of H. metres = migh
ngH
70000m TH=7000 It falls freely for a distance of 7 km. 2. (a)
Heat received by each ep1id
ass x ep.ht. capacity x temp. rise.
Q= mcd
Rate of heating =
Since heating rate and mass are ̇constant,
Rate, of temp. rise, is in- versely proportional to specific heat capacity
= mof: where / w constant.
Therefore
ma constant
constant.
(1) The slopes, x0-1 and yo-1, of the graphs show the rate of temp. rise of these two
olids. The alope x0-1. is, steeper than that of y0-1
Solid y. haaa
larger specific heat. capacity:
(ii) The plateau. y1-2 is at
higher Level than xi−2,y melts at a higher
temperature, y has
a higher melting- point.
TIME
and
(d) Heat required to. melt the Bolid mi
constant
(Rate of heating. Vant waas.
are constant)
力形熊過在在
heat of fusion of the solid, (toL)
(y1~2)>(x1-2)
Solid y has a greater specific latant heat of fusion.
(iv) With the same explanation as ̇in (1) y2-3 de ateepex.
Liquid x has a larger specific heat capacity.
(b) Mass df water, m = 0.25kg
ap.ht. of water, = 4.2KJ/kgK Temp. rise of water e = 36K Time taken t = 3 x 180_s. Rate of heating
0.25 x 4.2 x 103 x 36
210 J&
-1
x 60
Keeping the heating rate constant, the total heat produced in 10min da
()t 210 x 10 0 x
60J
This amount of heat is used, to boil
Away 56gm or 0.056kg of water. Therefore,
0.0561 210 x 600
210 600 I ==
-0.056
= 2250 KJ/Kg
The epecifio latent heat of vaporization of water. is 2250KJ kg. Questions for this week 1(a) Define the boiling point of a
Liquid?
(b) How ia boiling-point of a
be affected by (1)pressure liquid and (11) impurities in a liquid? (c) Distinguish between boiling.
and evaporation.
(4) A water-fall of 20 m high is
used to energise a hydro-electric generatornata rate of 10 kg pen
(1) What is the power generated.
if efficiency is 100%? (11) Practically, 1/4of the worl is useful, the ms jority is wasted in warming up the water What is the temperature rise: of water?
2(a). Explain what is meant by dew-
point.
(b) What is a saturated and an
unsaturated. vapour pressure? What is the effect of changing. (i) the,
(ii) the temperature on
the saturated and the unsaturated vapour pressure?.
(c) The relation of saturated
yapour pressure of a liquid and ite temperature is. tabulated, as follows:
Temperature
Vapour
pressure. (mmHg)
0
10 20 30 40 50 60
1.69.217.53154.592148
Plot à graph with these data and deduce:
(1) the pressure at which water bolls at: 35°C fure at wrich. (11) the tempere
water boils at 40 mg, (111)
the relative humidity when air temperature 18 15°C and dew-point 10°c
(iv) the dew-point when air
temperature is 25°C and relatio humidity:90%, and
(v): the room temperature when the dew-point is 5°C and relative
humidity 75%.
敎響
僑
教
育
經濟不景,學生不足,教師過蹤,
教育司署今秋開始
可能推行四項對策
·休小
警署須
人增
學員
今人不
秋員能
起調在由
改教津
辦育校
中學
學院教派
傯 持柴 剪然
上下惠學糲胤
凡有」的字眼來形籍,一集瓦第十三行情
教育隨筆
能
·吳警方聯絡。
黑學生被捕說起
.香港教育專采人戶協素本年一月十一日在橋
從一百二十名
代學鐵會辦絡
统遞及
忖此問題?' 八名年齡在二十一歲以下之犯有黑社會案件者,
甄内政府,是否詡爲黑社會在學校中之影響力。 。此外,在一九七四年所拘捕之一千六百一十 「洗底」.少女如何避免失足等。 益葳机,若然則政府會奴何指示成協助各學校廉,以及學生代裘共同處班遭期同題。 |接獲八宗有關學校投诉蝮疑黑就合份子髫助之報,在受到威脅時如何請求帮助;戶入會者,要如你 在1月11千11日立法局會乘上,高苕滋醬 飈兵也躉来,我覺得是值得抄錄在下面的: 教育罚隔邀的答覆录,在過去一年,警方只 迅速採取行動,平日則派員來投宿,教導學生院 二、舆警署加强聯絡- 發生事件時安求警方
「其中,張,了「只」和「只
此問題之認識。
社會份子,或是爲了怕影響校譽,或是照人物 我們知道有些學校的主持人,明知校中有黑 有」的字醌,意思是數字並不大,情况並不嚴寬 對的珽會及學校啸導員應使其工作落置進行。 五、學校除畢辦樂活動外,更可開設其他
· 四、鼓勵學生組織有意養活動,不少形狗
·W、辦作文及演比賽等,使學生加时
,不敢輕易驚動警方,所以投訴的案件不多。 的學生被捕,我覺得這是一個令人震驚的大數字 個罪不起,他們設視而不見,或極其他方法處理各類有米華活動。 至於一年之中,竟有一百二十名黑社會身份 切間,禴仔師生關係。
·黑势力拳入學校——且不論其嚴重的 七、教育當局及校長應給予敦師方信及自由 *、班主任要關心學生,了解學生;作家庭
學字一頁 行改行正常榮
敦學年新參期爲一頁一部學 印便秪學前一和元爲:質第一八個學年
代
吃下本多
用宜 學供料能
會報蒧科教學規解
翼,五百
在人力之使用上達到最高刃能之發挥。. 呈現敦署,由教署在官立及津貼小學中將屆時多出之戰師調往任致。
·新猷之二期與預料於今集退休之官校教師及教署官員有關。以一度情形而言,退休之教署人员 柏极本學年之新生人數更少。事實上,本學年各官津小學已有不少學位空出,甚多班級並不足額,一個很高的頻率,足以說明黑社會深入學校的情 在人力方面,亦不例外。在節約圓則下,開教育司署下學年(九月)開始,將推行若干新猷,以求 據可蠹來道透,我第一項新猷保类官捃補學校教師有關。據廨;根據人口耕計,本港小學 適的兒童之增加率在最近數年均告放,故估計今年九月新學年開始時,小學各年級之新生人數上。因爲平均三天就有一個黑社會學生被捕,這是進行上述工作。 (特凱)在經濟不景氣下,香港政府各部門皆厲行節約,不論能很及資源各方面均予搶省,即 形成教師人數超過飯局所定之一點一比例。而要望下多年,比抓現線可能更為明顯。致爲節省队已相當嚴食。因均被捕的餅這麼多、參加了黑:何,只是亲所公認的事實,希望警方、教育司、期限 方 - 不致浪費公案,故現已內定下學年各車補小學如有致師空缺,學校將不能自行招猲教師,而須 社會而未被捕的數目當然不止十倍於此。假如治 校方,家長一同就照此問題,使以百萬計的學童,教官難
位新資尙之學
我開則多官
贊始每機員
|安监局和敦育當局需爲定性。成不能”的二行:决学改正也,故字;第七
在意料之中。
有執教中學低年級學歷者,多出路。 朗撥入附近之官校上課。此舉}增加中學學位,再則亦健教育學院畢業生生成現職官小融師而具 上述消息尚待有關當局證實,惟在小學學生人數不足,又逖港經濟不景之今日,則此等措施亦 新猷之四則爲液境中學學額。開今年九月開始,將有若干間官立小學改標中學,而原有之學生
以前將節開支。 獲准在鞏補學校任教,以期增加職位,使現職教師及教育學院畢業生多位莱a. 。含不致送淼現蹤放師及教育界之新血出路,由今秋開始,退休狄署人員及官校校長、教師、將石 | 市區中心八瘵嗆蒗中一 四五○○二一。. 爲普遍ė惟因現時教師過閥,而改育學院之畢業學生則每年皆有數百名,亟盼學以致用,爲得敦聘·七成三〇八)。二樓 電話:五
新書之一這部份就署與屬人員,為體能教育學院任教。此提示发響計本身之段员不會成少 九龍瑪利諾學校
倫敦商會夏季商科試
會計及簿記 考期共五天
下月開始辦理報名
由校方抛師,而其他生可用自生名參加。 教育司海外考試組染粘强昨日俪報名于斜時表示,滋生概
育司署考試組案取名表格。自修生並親自將填安之報名表格溯商其本
自修生可由二月三日起到九龍仔東遭三百九十三號政府合锟十一排致十五元一共十
外卅日用的作兩份:
; 这带 學蹀分起考 際一
在元 號道八起粵用餘,多而爲及日
毒 演 至每語 婚 簡 狶主 中政,闡 三八丹 時每 。 安
重設 中难
一二,退學師 的過年1
校秀。中在下定由和訴九婚法庭共港, 那學 在下二、活在 活實 發
比於七法明、有八婚。費送北午月歐料 助習 數本
科
【關躇 五樓 角七せ參內及
日學 諾開半會貴寒容及槛物開 及部中幕, 国物畳加節別游始
北之二學典請二 品及。自出藝在二
學陳
三號政府合署十11樓,敎育司寧海外考試組會計部用現金或支票繳付考試。有開著相機外 偏软疣會一九七五年此科夏季考試的科目,考試日期及考試費詳列如年兩儅 訂婚姻訴訟法 自修生須於整委辍名手續拶 - 於二月十日前逕往九龍廣東道三百九汁 法和收養兒女例题的
討論毒品問題
: 六月二十六日
七月二日 六月二十七日
六月二十五
新界中小學教師
.二十八元
二十八元
考試響
,展開一串節目長及各界人士參現。
|學校二月二日開始一名各科成辦,歡迎來
「港 九龍瑪利部之開放日,到時展出
歡迎校友及社會人士參加
利持商。物名友士位各警時校只
用修醐
由人之及品
諸豬大聖三成元餐、七生賣贏白。迎展
東聚會讓時荻野假時 扭招晚晚 家田
科
第十敌十一)
千入至四頁字正行险
行推四巍十;四決 来改
|清宇其 字一 第行字第 字正
用,第五字切去字:
四六行政;得:頁網
九龍瑪爾貼本校聚溪野 開學:二月三日(星期一) 「耀話:K九六○ 校址 旺角花園街七十五號
·高級彩色電視工程科(lil)無綫電報 科(四)無綫電及電視技術科(夜校 ) 監督 校長腿交熾
東南無綫電專招
篇二午·爲建午非 料指各會戰時舉 午 中月爲 瑪主三紮 容出校人是有行十。
稍下
法较二負司 榮琱校二出李
枝
五极晚下
·修改後置書仍可適用
二十五元(南) 三 上课:學費四十 |時卅分至七時,在港太 定期下月十四日開始播|鼎修改之內容,考虑是 校外義區新市區中心上映。教育電視小三、 否須要購買新版本以供 革觴教育書麗節目,輕「告各校可会系列有一
世界
校學程工司
|電校開于 攤生招
「話址 輝隆 成多國
1:1及岸名願,
一般色介氣
慕德中英文中學 招寄宿舆走讀生
女生宿舍,事人員實警涉,全日上
台語名地點:香港域、教師及學生手脫症將中國語文科三年段(二)中學部桕t(i心中文部,中一至中四精靈生。
百八名參加研習| 本港大專教育
〔11〕「初中數學,電話:五四
本
備與港
劃之跑步與繁榮。
青及直傳小組爲一般教導十至十五粱學直之師,也著此有機會對於本猪之大專教育與本人等所 胡仙女士、岑才生先生,白約翰會督、列幅大第一 现死讯教育司與尞毒常務委員會之教,部午角會說:今天本人能出席費食常實萊惑榮宰,中包括安子介先生、丁龍照先生、邵逸夫先生,
一月卅日胡鴻烈在香港离直扶輪社知村集 1月辭職,而由副董事長黃官平先生出任。校董 任金爲中文大學投資會主席。於一九七一年十 品,掷仁董事會原由赞设強博士任主席,自其被 學生之應性,熱愛社會,與他人合作,以求取社 一畢業生。樹仁書院之教育宗旨,爲培養幣一
謀師的
深散前創,超
示,對此問題在在做散打 前,因爲本人異已故之廚迺调先生,常在崔候镇.學生入学悌件與中文大學相同,計凡投放出一
·崇學業從事吸毒之最有效抵泆5:
|港大校外課程都
私政有,肚。生氏创先
坐在, 大秽區衡即
本,本權,
六发
著。,包之生而
春季新課程三項教狀物,他被中国大学排
衛生、數學及法律
無食品
软作于程承誓中科糖
·【特訊】香港大學一食術性及安全挖席識。 專與中學,創辦於一九七一年,大專設在跑馬地之功,而第二部份,本校學生差不多佔十分之一
校外課程裔春季墁歌嗎 主要對象爲各教進行中學則在高仔於遠,目前大專部學生約有五九。故倫敦方面特派員來本校甄試,而本校學生 学
飲實用撼,生菜
在日粵及迎
學七期,藥由興
大儒專。
鈕時五定人黃
*時一授
曝本港社會之需要。樹仁書院共分七飛,計爲中 建中學一所,並再堆德大學一所。本人榮伯仁
成
3211-
中
本瓶越九级二
五
• 【2】英文部-F1至 F3班生 -
KK1
√印機用 宜加錢秘
香港商業專科學校
二月份新班通告
英語會話:中文會計算記
·運出口文件及計價 打字 瑭打中
商法:經濟語:別文記 商業札
章程及時間表來
中医辦事躇-裕成商架大厦一四〇一案
日夜校校址:北角英皇第一二九號二樓
尖沙咀柯士匈獾八十一號一樓
單鹹期期、
本
E
第三惟=容改
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日立牌十八吋全原子粒彩色電壓機英羕外型,
版蹠载頁一第張六第日十二月二十年寅甲歷要