1975-11-20 — Page 19

四期星

日十二月一十年五七九一腊公年四十六國民慊中

崇正總會聯合港九各團體歡筵

中華民国私立教協考察園

午六時假九雅璜華酒樓歡实。... .. 甘美、黃、紅、蜜、日考察教育,香港米正議會聯會港九各團首度 中華區西私立教育事業協會教育考察團,十八日午抵港,嫁

THEEJ - EKERLER KERK - ENERIK 聯龍慧會,中原客屬會、惠州高郑病育、嘉張五屬同鄉會、環縣商會, ※ 主方四楂計有:正进會許讓成、黃就安、黃煜、杏林、同鄉會 五舞团黼會陳漢宗代表致逸,泰近平我同客甜氣主盡歡,他况轎烈······ TEST - BEETEER· ERBRIEREN - KUENE - EEN SKREUZORCE - BENGETIKKER - WUHRER BHERESE - PRZECZEKASSESRINGENDY-TE -*920BEEN HINESE, FRERKF9B6ER - KEE

**R - HER BESLE

儒鋇訊就安等二百餘人。 楊美整,使幹事方淑萍,秘書商業明,

灣分會,惠州同鄉會邱洲分畫、集成 書公司、英倫 商議會陳秀安、牙買加 考新盛油名如下:團長察,

會州會明分鄉林熊

墨 ̇路圖會、形的

#、

·

來、繁难明、杜振乾、史妍光 林中、黄金夾、孟根華、許兩傷、丘 選、淇奥杜、求,張康风

·朱》、林士真。

郭日僑華

明年校際音樂節

間團團長蔡亚萍(右)、副團長馮良杜 曾爲中國私立教育事業協術教育制

刺力:

静娴

性吸力

**RSOS- KERENHE

各業 保

考慮接受,八成) 因此,任何罪名表格於上述日期後交到者將不會的手法,並且重活分 照本及音樂懟摄斯不再設有最後黑名日期、出爭勇得插取各项安 11十八琪,參加报名明一行撤止。独一脊料供實地價查之用, 三月十五日至四月三日舉行,比賽項目將有五百 - 拌楼网套組準備有關 (RE) BEZBAREKNEE-154 ] · ENKREUKKE

橋 香港大專同學會從事

校内黑社會活動調查

會學

迎大事及中學何事參 嗽力!除安良」, 誤育之只號爲「賞

(EE) BÉKE FENHERRKEI TIENE BAK! 歡迎大專及中康間參加工作

至於近期發襲。十一加工作。

有教僑韻頁三第張五第日八十月十年卯乙 WAH KIU YAT PO

张,分,试初

興就是法攤離而毪肚等。

་ ེ」 。་་

立鐵一校於

的主央在於慈求現時唯一限,有張貼他盡。

校內黑社會活劾健委」!帶學校医领域,亦會 七月底正式査佈成立「伍,九城,九散望 日益强联之第-於本年於港島西區堅道一帶學 「黑茶會」成立目,經濟因素,印致北 | 美術」,簡稱「黑委會美術在各獲民政署,公 立圖書館等機構。由於

行十二及田徑運點 月十五日供幾葛斯堪

院於上週六十一 [韓饌]中文大事

BUDAK.

中大新亞書院

·私人接觸,阿投三分析資料,四

-EBWE RE 8-(11) KREN. KR.

E-RAJEKOVE PS4-(1)KER KÉZ-AKSETE 举校內黑社畲活動的眞:「魚委實」的工作书法四百多人,會搖氣

多色系豪,百變

凄會活動案件的拥查過,黨報告書,工作期限以全屏紊期『勇者圓 等;利用實在的校內熹檢討階段,八五年 虎門角逐,經濟系

BERK<HAN-7 |

辦尚可從黑

的典長勤作

皂,有求嚴插攔

斯邦助中校面之

* 學區的不

組

,左下)下午校校長樂姁明股務報台 掛,先後會語警方「夫人狸进及頒獎。(左上)上午核校長和兼张数 ̇「無类會」成立之一旺角民砍可黑主任更换方致詞,中一赛

分別獲得提供有關禸料

,教育司學有關部門,

「反馬祖」總整可投人

HE#E-OKOBE

接受各界人士的投訴及

・晩時至十時

八月下旬,漢期1

HOT-LINE ) --BAS

,向杜雪人士,中泰界

曾於九月內透過赖界

及起錄工作。

́(U) GREE··

BEER - ANAK DE34

均有各大專院校的同學

--ERENCE -

(B)當值員制度

經後體安門

一開的將料,

同夫

DE

D903 中學會考試題預習專欄

(3) 李國榮。

化學科

CSTRY

Question: 1

(2)

a. (1) Three isomers are possible

OH (11) HO

(1) HO

(iii)

H

HO

(i) & (ii) contain -OH Structu group which was proven to be pre- sent by the addition of phosphorus. pentachloride.

R - OH+ PC15 — RC1 + POC1 + HC1

Yet the addition of magnesium metal to these compounds would produce no change.

Since magnesium is a reducing agent, the only possible reaction is to reduce a positive ion, hence Hypothetically

2y+" + niig →→→→ 2X + någ*

+2

hus the third structure satisfies is condition since it contains a lisplaceable hydrogen.

2H* + Mg

+2

Mg +

E2

For the compound, with structure.

(iii) the reaction would be

20H COOH + Mg 20H2000Mg + B2

(2) Its reaction with sodium hydro- Fxide would be

CH COOH + NaCH OH2COONa+ H2O

a typical acid-base reaction. The products are sodium acetate

CHCOONa, a salt, and water.

(3) Acetic acid CH3000H can be

pared by the oxidation of ethyl alcohol, using chromic acid as “öxidizing agent.

CHOH

CH3CHO

C2H5OH + 20

ethyl from

IOCH COOH

CH3COOH + H2O

acetic

alcohol chromic acid

acid

Structurally this represents:

HH

H_C~C~O~H + 0

HH

then

H

+ H

K

b. Three isomers are possible.

(3) normal pantane

H H H H

H-C-C-C-C-C-H

(ii) iso-pentane

CH CH

H-C-H

(CH)CHCH

HC-CC-H

H-C-H

(iii) neo-pentane

H

H-

(CH3)40

Question 2 (1) The cation may be sodium (Na+)

or potassium (K). Cupric compounds ́are unlikely since they are mostly coloured. They decompose readily on being heated, only copper oxide which is black is relatively stable on moderate heating. Ammonium ion is also unlikely since they decom- pose readily on heating. Mercuric ion is also unlikely for the same reason.

chloric

acid

acid

Hypochlorous acid is unstable under sunlight, which is an energy source for the reaction...

2H001 2HC1 +021

The colourless gas, therefore, is

oxygen.

am

→ slope T (where slope

slope

0.6

4π2 2.43 9.748

(x).

0903中學會考試題預習專欄

(CO 2

物理科 2). The result obtained from

()

3

何輝明

2a

-1

+1

3

(2)

(2) The anion would be carbonate

the addition of calcium chloride

solution rules out

1.

(i) C1 (ii) Br ̄ (iii)

all of which can exist in solution in the presence of calcium ion.

(1.e. they are soluble calcium com- pounds.) The addition of dilute hydrochloric acid to a sulfate in the absence of heat does not pro- duce the oxides of sulfur which are strongly acidic.

Therefore the only possibility left behind is carbonate ian (CO

(3) Any carbonate would react with hydrochloric acid to form carbon dioxide, which would readily tum calcium hydroxide solution milky due to the presence of the compound calcium carbonate in suspension.

(aq) (aq) CO2 + Ca(OH)

(g)

CO2 + H2O

(g)

Caco, ↓

H20 (a)

(4) The white precipitation was

probably calcium carbonate.

+2

-2

Ca + 003

(aq) (aq)

CaCO

(5) As in (4) The gas would probably be carbon dioxide, which is faintly acidic gas.

Since sulfate ion is unlikely to be resent in Y, oxides of sulfur are improbable.

Question 3a.

(1) Brown fume would be observed

when the gas in jar B entered jar according to the reaction.

2NO

2NO

(g)

2 (8)

oxygen

(?(8) nitrogen dioxide

nitric oxide

(2) Yes, water would enter jar C.

since the nitrogen dioxide formed is soluble in water. But oxygen would be left in jar C since all the nitric oxide in jar B would use up only half of its own volume of oxygen. Half of the jar would be occupied by water and the other half would be occupied by oxygen. (3) Yes, nitrogen dioxide would

dissolve in water to form acids according to the equation

H2O + 2NO

HING

2(g)

3(2)

nitric acid

+HNO

1200)

nitrous

acid

(1) When chlorine gas is bubbled

through acidified sodium bromide solution, bromine. will be displaced. out..

The solution becomes sodium chloride solution. The red color is, bromine in solution.

1. 2NaBr + 012 donically

2Br-1

(aq)

2NaCl + Br2

PHYSICS

1a. If OA and OB are the velocities of A and B respectively, then the velocity of B relative to A is given by

OB - OA = OB + (--OA) which is represented by the diagonal OC of the 7 (-A)0 BC.:

Therefore, OC is measured to scale, equal to 50 Km hr

36°52

The notation of B moves in a direct- ion of SOW relative to A

30 where tan ✪ =

(1.6, 336o 52) b(i) If BC and BA be the Ox and OY axis. The L-shaped body is divided into two parts, and their co- ordinates of the c.g. can be written as figure shown

(12 x 4 x 3 ) + (4 x 4 x 6 )

(12 x 4 x 6) +

(42426)

416)

(',')

The o g. of ABCDEF is 3 cm from AB and 5 cm from BC.

(ii) The wt. of L-plate 64 x 1.5

9.5 g

Take moment about point B Clockwise moment – Anti-clockwise

96 x 3 P x 12

P24 gr

(iii) The dot-line joining B and c.g. is the required plumb- line and is the required angle.

tan e-

50°58

Suspensio

the beb

fig. 10-1

fig. 1c-2 (i) As fig. 1c-1 shown, 1 is the

effective length of the pendu- 1um. (From the point of sus- pension to the .g. of the bob). (ii) As fig. 10-2 shown, From A to B

to C and then from C returns to B and to Aï

(iii)lf the mass of the bob is

doubled, the period of the pendulum is unaffected.

bromine

2) + ( = {(8)

-1

201

(aq) + Br2

(g)

(iv)

(m3) T for 50,080...

(S

(2) When chlorine dissolves in water

acids are formed according to the equation:

H2O+CI, HƠI + HOCH

hydro- hypochlorous

022 0.4 0.5 0.811.0 45 63.5 77.5) 90 100 0.9 1.271:551 1.82.0

0.81 1.61 2:40 3.24 470

»song

sburs depresion

(ii) Molecules of glass in the tube

exert greater forces of attrac- tion on the water molecules than the water molecules them- selves. Water rises up the tube until the force of attrac- tion of glass on water equal the wt of the water colum. (i.e. Adhesive F-> Cohesive F.

The force of attraction bet- ween mercury molecules them- Belves are greater

n those between glass, molec mercury molecules.

This causes

the mercury level to fall, until the force of attraction of Hg on itself at the surface equala the pressure at that point. - (1.e. Adhesive

b. (1)

1. Fill a clean dry glass- tube with Hg, and closed the tube with finger

(beware your finger is not wounded)

Torricellian

·Vacuum

Cohesive F.).

the tup of the tube

Inverted the tube, note that there is no bubble remains at the top of the tube

3. Put it in the mercury dish, and remove the finger. The Eg level. falls to about 760 mm since air has been completely excluded, the height h represents the reading of the

A Pheric pressure.

(ii) There are 4 objections:

1. When using water as the baro-

metric liquid, the colum s too high. (about 10.336 m) 2. Water wets the glass tube

(Adhesive force between glass and water)

3. Water vapourizes easily 4. Water is transparent.

c. In figure 2, Let the presaure the air space inside the faulty carometer be 2

(1) From Boyle's law

(900 - 650) = P1

P2

200

:(0):

The atr. pressure F, is equal to the sum of pressure of the air space and the mercury. colum

In fig. 1

PoP1

+650

In fig. 2. Po≈·

= P2+625.

(2)

·(3)

From equations (1), (2) and (3)

Solve for P1 P1=100 mm Hg Ans

(ii) Solve for Po Po 750 mm Hg