1982-05-27 — Page 23

報日僑華

日七廿月五年二八九一曆公年一十七國民華中

四期星

思想危機

教

巴消耗了二百位蟻天然氣。氣 一根是形势喜人。到目舢商止,我們

扯頁岩中還有七千億哦,但其中筒

對我們總盘的估計甚至還商

百七十點•科学家們估浙,未發 噸,這少我們已經消耗了六百億劇 世界可開探的石油總饼造爲六十億 期概的估計,總儲量至少也有一千億 百三十年左右。天然氣的情况也同, 一況下,我們的儲油量可足夠使用 一。在目前华任油畫三十億的

百五十億顯。總的說來,即使按ㄜ 一 經濟地加以晒斑的只有一千七

估北路六千五百億噸。在油砂和 :悲貌的估計膈二千七百億噸,榮

發生產出一千五百億石油。

,已探明且業已證實的油為八

一九二翌年,地質學家們估計

一年地增長。

- 都滿萡了,多數工業國的一般被 一,但大家都知道石油儲備暨還是年, 站多數袞荷運行,長期以來無需 減少發電载,不管消耗了多少石油

有道理的:各主要石油公司的油鸨 人們至少暫時不談能源危機是大約在一千八百億順到四千位順之

化,則能強危版、環材料危機、玻境危機和世界粮食危機。. 成千上萬的動植物品種以死刑?沮丧我挑遷下列四個主要危機分别加以研 立的在大肆掠近地球的原材料俊源、污染水土大氣、破壞生活環境、何處 一們的氨酶中?我們是否真正面臨威奇奇我們生活的技術大災難?我們是否一 JF·R·巴杜里作 雖實存在嗎?抑或僅僅存在於我 厌、描拣欲號的世界。這些危機 看來我們是生活在一個危機四 坛危機、粮食危機、交通危機 潘源危機、原材料乾機、

教育學院畢業同學

研討營論師生關係

, 消耗亞的百分之三十點三,歐洲雞 新百分之四點六,竇趣的非洲大陸 十八點五,而整個中美和南美洲 小,其能源消耗量却不少於百分之

北美洲的能源消盘佔世界 人足足超過一千多倍。一九七九年 大量需求。美國每人的平均花嬌量 義煮。第三世界明天對能説就會有 繁榮因而自鸣得就高嗢技術和經濟

或二十年內對世界人口只有對性 ,

算,可繼緻用五百年 9 ;

間。祗煤和烟煤的景甚至更爲美 或茁设,上面談到的能源儘量 201) (2) 慬消耗百分之二點] [轉載「現

約為一個歐洲人的兩倍,此尼福爾

·應該停止發展的人不外是些利己主 益地長。那些享受程工業化國家的 影響的危機。世界對能離的需求日

AR168 - RESSEN 一赵匡正的能源危機。一場在十平

日前所有可利用的能猷的明死受阻

·千億噸,按全世界目前的耗煤蔔計 ‘雖然聽起來有些荒謬,但如果

好,目前已證實的儲煤量爲一萬四

已譯成十多模文字,

後任自由撰稿新工作, *瑞士工業界歷任要職, 的群佣工作,在西德及 參與世界能源問題預報

·布粟斯勞市,六十年代 巴钍里一九四雰年生於 :「思想政裢」作者-

了监委全本介留了他所 師生關係。是省活動除,東西 90 [假何船掌會所學群第三 簡,又將對不合艮的事一親等方面的意見,結果 屈教會研討營。主題爲「物存疑、分析、逐步 將於稍後公佈。' 會於本月廿二 廿三日交貅莲守肚會的道規、課外活動、和學生接 教育學院畢業同學積極的人生理想;他們與學生就敢與學的態度 崔,內容主要間及教師

·又該會現正進行一 優社會上的中流砥柱。 VE

生關係是在學在教

係的方法及其客出 分組討論了改善師生關

VERNEUSES

經歷的師生關係外,並

四所抱之患法 - 同時又中心

透過立像造型設計來麥|文化,

力和学生主梨接受数化 種隔係只有在敢師的努

的情勢下,才能建立良」研討

RENGHEUREARSTYRYNOS * BETRA - SEEKE 藏所有會經參與東西文化 中心活動者成爲會員 - 俾

·友,加强彼此認識-並年 日成立,現致力聯絡各校

·查技術於村年四月1

鈎包括康樂活動及晚宴, 探討有關脚運!日節目

五 研討會,題為「香港經濟

,座沙田香港中文大學舉行 友會定於六月五日下午假:

【東西文化中心香港校

一

他們又指出:良好的師 好的師生關係。同時,文化,增進國際瞭解作出贡献。

「習的目的和目標」的基十五日,查詢鼂三十三五八六一本英 慾,使他們在認識「學」選人參加角逐「優秀校友獎」,截止日期是六月 獎裹,培養學生的求知,交國際校友會,此外故命亦促清思港校友提名俊 個和諧、愉快的教學環對會議主燈及內容提供意見,於本年七月底前 N 生關係是拧敎師能在一坡舉行之東西文化中心區蹀校友會議,歡迎校友

育教僑華頁三第張六第1日五初月四閏年戌壬冠夏

園參導龍R

無味餘球

欣餘,思紙,吳漢

ESKOLE-B36

車至粉嶺百鄗村田國礁 辦之個案有一

做,謝碩女士,黄

嚴志夫婦,她案平夫人‘有-

份證據而申诉人處境值乘同情者·雖由其 柏夫婦,設立仁夫婦, 香港有關部門處理,並拿重他們的决定。但如案

• KEKERE NEED 大略,部門恇絕辦理或不予批准,本人可考慮母串深人

前已數次指出,党惝犬使所辦案件,交由英國或

和小龍情香丽

實現,黃昏,陳專班 和精神,全看至伊。」

·陳靖生,宋你權:馮品,健巳撦到蜡城服務前,轻而且所付出之時間

太湖時七十分鐘,據李氏讚:「家人最近所接」

盆觀師總

栽粉學演

展嶺員講

田班

WAH KIU YAT PO

化努道效師

研|友|港|中|文|

討會|校|心 化西

途前濟經港香

行舉大中午下日五月六

迷中藏友日:做向探前

月一礎上,樂於追辣健康,呜。()

初 龍總演講班 思米,吳組來客數十人 還滿目,我揭展。

澳門寃情大使

◎ 免費代辦服務

云港訊Ó澳門消息:「澳門文學院一院長李

會演講單同人,臨粉嶺錦路線土窑於日前正式訪問香港政府人民入境

由钢盆栽石山蘭花性.

之条民。 元,肏花 澳

1982

「中學會考試題預習專欄

化學科建TM參攷資料

明德出版社提供

Suggested Solutions

Chemistry

Paper

rit should be noted that

the answer suggested here

as very often one of the

everal posibilities.

*

(i)(1)It should be

clamped close to the stopper so as to prevent the cork lining of the clamp from being burnt. (2)This is to avoid

the cracking of tube A due to the back flow of water condensed at the mouth of the tube. GìThis is to prevent

"sucking back" of the liquid on cooling the tube A.

The set-up would be as shown below;

delivery tube

HTH

freezing

mixture

beaker

(Lv)On heating, besides water, the crystals also decompose to. give sulphur dioxide and sulphur trioxide. When these oxides.

divolved in water, an

eidic solution is Szobtained, thus

causing the water to have a pll of 4. (v)The residue is

iron(III) oxide,

(1)s(-)+21g*(aq)

Cuˆ ˆ (aq)+"Ag(s) (1)(1)Some silvery-grey

substance would be deposited on the surface of the copper coil.

(2)The resultant

solution would have a blue colour (iii)M(Cu)=63.5 g mol and

1

~ M(Ag)=107.9 g mol

Let the loss in mass of Cu be, xg,

Cu+2Ag

1

mal

67.5g

215.8x

0.70

02921 g

(i)The substance in test

tube A is potassium chloride.

(**)N}}, *(aq)+0HTM (24)

Pluce a glass rod moistened with

cene HC near the mouth of the test. tube. Dense white fumes would be seen. (iii)It is because

calcium hydroxides, on heating, decomposes to give off water vapour, thus causing a loss in its mass. v.The_solid residue, în

test-tube-C is

((a)

enlgíum oxide. It is commonly used as a drying agent.

(i)T might be potassium

·(or sodium).

(ii)X might le mercury

(or silver).

Hg(NO3)2 →→→→→ Hg+2NO2

(or LAENOZ

2An÷2N02+0g)

(ii)z is the more

reactive metal because it can react with water while Q

cannot,

(iv)It is the move

reactive metal because R, being able to displace H, from

acids, must be above H in the activity series while X is below I in the activity series. (v)The order is: T > Z > Q>R>X (iv)The less reactive

metals are obtained at an earlier period while the more

reactive ones are obtained at a later period. It is because the less renctive. metals form leas stable ores or compounds from which the metals are more readily extracted,

(i)The suitable apparatus.

is a pipette.

[*(og)+0H ̄(aq),

-- 10(2) (iii)Average volume of

0.10 M Nao requied

= [(46.3-23.8)+

(23,9-1.2)+

(46.6-23,9)}

3

The data in

42Ag

2

2.73 co

mol

(2x107.9)g

? E

mass of Ag deposited

(2x107.9)(x)

# 63.5

net change in mass Sn(Ag)depósited

(Cu) reacted

2(1079)(x))

63.5

-0.70g (Given)

Experiment No. 1 are not used in calculat- ing the average volume because this is only a trial and the data are not necurate.

(iv)n(NaOH) reacted

22.73 1000

x0.1

-0.002275 mbl ¤ ̧•×H ̧Ð+2NaOH

1 mol

2 wol

(c)

N®¿A+(x+2)H ̧û

n(μ‚Â xH ̧0) reacted

-xn(NaOH) reacted

7x0.002473-

-0.001137 mol

múlarity of the acid

1.000. 25

=0.001137x-

045 M

of weid 250

x0.045 1000 -0.01125 mol

~(90+18x)gmo1.

250 cm

250 cri of acid 0.01125(90+18x)g #1,43g (Given)

-0.01125(90+18x)=1.

x=1 99952

The value of x is 2

(i)This is to provide conducting medium.

(11)(1).

purple patch

filter

paper

(2)The permanganate

ion (Mn0

responsible for the purple colour. The purple patch - would move in the opposite direction, i.e. towards the new position of the positive pole. It is because the

permanganate ion,

being a negative ion

D.C.

pole of the

(1)2 is a metal. X and Y bure non-metals. (ii)X, is carbon,

Y is sulphur,

Z is magnesium.

(iii)This is because the

surface of the metal

strip is coated with

its oxide which is not ignited. However then this layer is. scraped off, the metal underneath can he ignited readily. (iv)(1)Tonic

(2)

(electrovalent)

bonding.

(b)

carbon and oxygen,

which is then useil to

support its burning

(f)When chlorine.

dissolves in water, the following equilibrium is set up.

The addition of NaQ!! would remove the H+ ions, thus shifting the equilibrium to the right and increasing the solubility of Cl.

(ji)This can be done by

adding a strong acid into the solution. The acid would remove the Off ions, thus shifting the equilibrium

C120H = 001 Gi

to the left. The ionic equation involved is

I1*(4q)+01 ̄ (84)

(iii)Add aqueous

Tobtained.

H2C (1)

potassium iodide (KI) solution Into some swimming-poo] water, a pale yellow colour would be seen, This is because Clo

has oxidized the I

ions to form iodine, which then dissolves in water to give a

pale-yellow solution.

→→ 12+2017

Leathe

1 Swelling

separately.

to dryness

IV. Evaporate the

Liquids

into the remaining 3

KCO solution

restaing

TI Add a little af

"other ↳ Liquids containing the

11. Adding a little of thanoic acid to 4

liquids

Spell of ethanolc acid Sarli uf ammonia.

efferrearence would have g

One of the liquida

effervescence would give it One of the liquida

No residue

Solid residue in

Tébe

seid Tube containe ́aqueous.

carbonate It is aqueous potassium

Contains acpeneri

It is hydrochloric, seid

18

je ja distilled water.

It

is

sodium

chloride

| | | (1)M(CaC0_)=100 g mol

n(CaC0–) mixed

(v)It would continue to

burn for some time, giving off white clouds and some black particles in the was jar, and then would be extingui alied. This is because a burning magnesium evolven so great an amount of heat energy that it decomposes the gas G (carbon dioxide) into

1,0

0.01 mol n(HCL) mixed.

40 1000 X 1.0 -0.04 mol

Caco2+2uc!

cammonia i

CaCl+

1 mol 2 moi

That is, 1 mol of C&Co. reacts

Completely with 2 mol

HCT

Tent

Observation

Beduction

Now

IC1 is

CuC0;+2][C]

1 mo

0.01

in excess

CaC12+10+C02

theoretical of C

2. Ch at r.top.

volume

=24x0 1

024 dm

240 cm

Theoretical volume

240 cm

Actual volume

= 210 cm3

The wetual volume is

smaller than the. theoretical volume because some CO, has

dissolved in the water (iii)Saturate the water

with

byndding

small CaCO Crystal

into the acid before the experiment is storted.

{(iv)Curve Y is obtained

by using (1) RCT(an)

(b).

with a concentration lover than 1.0 N and (2) lumps of Ca€0,•

reduction in the rate and

the final. volume of

* Coy was not due to an insufficient amount of acid. This was

because

Сасо

lumps. reacted with, sulphuric acid forming, on the surface, an insoluble layer of calcium sulphate which thus prevented further reaction..

(1) B.

(ii) B

The repeating unit

D

The set-up is

shown below!

broken porcelain

glass

coated hest

With

trough-

water

(iv)C and D. (v)E, because it

dissociates to rive ions on dissolving in water.

(vi)The order is:

\\\\\>C>D > B > A \_\ (vii)B can be used as

soap. It can be obtained from oils

or fats.

(1)Three of the

characteristics of an equilibrium system

are:

I The equilibrium càn

be reached from both

end's..

II A reactants and

products are present.

11 The concentrat Tous

of all substancvy in an equilibrium system remain} unchanged under a particular set of conditions. (ii)Add an acid-base

indicator such as methyl orange iuto the the aqueous ethanoic beid. It would give? a red colour. (iii)Sodium hydroxide

solutions cần bỏ used. This is because it provides. OH ions which dần; remove H-0, this

-shifting the

equilibrium to the right.

(iv)eat the solid sodium

[(b)

* non-

ethanoate with a volatile acid such as conc H2SO4*

CH2C00 ̄(aq) +H*(aq)

CH_COON(aq) CH2COOH (g)

The ethanoic acid produced is volatile and collected by condensing the vapour The continual removal of the ethanoic acid shifts the equilibrium to the right.

((i)This is because they have the sune micber of electrons in their: outermost shell. (11)(1)The electronic

diagran for carbon disulplride (cs,})

(2) In CS, 0.N.

of C

is 4 and 0 N. bf Spis -2s

(3)They both have

very low boiling points.

(iii)The gaseous pir

pollutant is sulphur dioxide (50%)

(1)It attacks the respiratory

system.

(2)It, being acidic, attacks the rocke in buildings,

thus making them brittle

(3)It makes metals corrode more readily.

(iv)Remove him/her from

the laboratory to un upen space or give him/her smelling salt (NH4)2CO3.

I Light the burner with

air-hole closed.

II Adjust the air-holento give a non-Juminous flame.

III Pour about 2 cm3

ethanol into the test-tube.

IV Add one or two anti-

bumping chips.

V Heat the test-tube

a water-bath.