1966-01-12 — Page 22

百二第張六

第一廿月二十年已之夏

英中產 試題 預習專棚

一九六六年度

英中会考

物理科

PHYS.LEG.9 (0)

(1) (Solution)

(a)

BEAM

Bow

By Me Wing Cheq

PILLARTM***

*PLUMBLING

SCALE AND POINTER

JBELLING

WAH KIU YAT PO W

-九六六年

期

英中會試題預習專欄

陸永熾

化學科

BALANCING SCERN

(-)

CHEMISTRY (2}}

王錦釗。

日二十月一六六九一层公年五十五個接華中

SRH

|钔定懑座人二玄學三,劍

單磁力、職理堂該小叶遥例期樉谜 將印方負監會發眼中涵,告友您 骸朝榮,終於組學傢由

EPRE-

FRS -BHK-A

118-ESRA HEN ERE,

PREGABEN KEK KOS

ROGERNE ES-BER-ES 1

修教媟事

港區師訓班校友會

理范希賢剛方榮

選出新任理監

、李鹹陉、蔥雞

銀河北麻

「家父,喀占秦。郗任

4. RNA

1665 52.

BENKERK

(5)ØRARIOS-DEE 2 BEVER

. 會定一月計六

BLAM WEARING

K

STIEELP BEARING

0,17 The given metsis in order of seciylty are

Folassium, sodium, calcium, namestum iron

Potassium gets very vigorously with cold water with the

liberation of hydrogen, the heat of reaction being great enough to cause the escaping hydrogen to catch fire,

Sodium also acts. very vigorously with cold water with the liberation of hydrogen, the heat of reaction being sufficiently great to cause the sodium to melt, but not to make the hydrogen burn, f

Calcium also acts very vigorously with cold water with the liberatory of hydrogen, but more slowly that either potassim of sodium.

Magnesium does not react with cold water. During magnesium will act very violently with stream with the liberation of hydrogen

Iron must be kept red-hot while strgan is passed over it for any action to occur. Hydrogen is also liberated during the reaction.

10.2. (a) Hydrogen may be obtained from water by:

, the action or metals on water. (ii) the action of non-metals on water (iii) the electrolysis of water.

(1) we can collect conveniently a small quantity of

hydrogen by the action of calcium on water. This method would not be quitable for collecting a few gas jare of the gas. A rest-tube filled with water is inverted in a beaker of water. A piece of calcium is dropped into the water and the test-tube is placed so that the hydrogen liberated Fises into the test-tube.

四息有 意請張刊数 讚第在有

وب

低

商台升中指導算術科

播出時間:

第十三講

一月十二日下午七時至七時半 一月十五日上午八時半至九時

第八部分数香則

4. BIR

JAKIJUNK.

(2)概分數一出一切鏧歐料一個才离

转右阅城的分款,

(M) #÷(2) 2±(3)

$) + 63+7+mt

(#) 3 4 + 6 + 77

3

LABORATORY BALANCE

Raaze pear-bearing

Sharpness of agete Stirrup-bearings

Balancing-screw

@Lumbline and

evalling-screw

G. of the bean apart from the Dom-bearing

Possesses little friction so that the bean can swing freely

ensuring constant distance between them and the beäg-spring

Te adjust the weights of bath arms

To adjust the zerg reading of the pointer-

To increase the sensitiveness

of the palanes.

Large quant11185 of nydrogen may be cocained by passing steam over red-hot iron contained in a hard-glass combustion tube. The combustion tube must be heated continually by means of a strong bunsen flame so as to keep the Iron red-hot. The hydrogen liberated is collected over water in casars

A

It is based upon the Principle of Nomant which states that if a gody is in equilibrium the sum of all anticlock-

ise ments of forges about any paint is equal to the Fun of all clockwise moments of forces spout the same point.

A

Lers and p be the unequal Lengths

vne two arms

wde the weight of the substance to be weighed

With W on the left side war and, Ry Principle of Moments!

(11) nyaregen can be obtained from water by passing steam ovBE

hal chke. The coke is heated. In a mulite furnace.

e product obtained is è mixture of carbon #monoxida and hydrogen,

(111)

ine carbon monoxide 28 removed by passing the mixture of the two gases through an ammoniacal solution of cuprous chloride, and the hydrogen is then collected over water in Ras jars

Small quantities of hydrogen are obtained in the laboratory by the electrolysis of water, water acidulated with dilute sulphuric acid is put into a Hoffman's voltameter When direct current is passed through the voltameter, hydroger is given off at the cathode, and oxygen, at the anode This method is not suitable for enlleching a few fans of the gas,

Hydrogen 18. protilised on.

ale, by the Bosc process

y blowrig steam throgh

Fract

120 JRING TE

****

With W on the right-side pen

Equeting (1) and (2)

28.8

250

► 28 6 ▼ 31,25

230,00

HONS

monoxide año

The water gas is mixed with more steam and passed over a catalyst of iron oxices at 500 ̊C., when the carbon maŋoxide in the water gas and the steam combine to form hydrogen ana carbon dioxide.

12:0

Steam

(2) (Solution)

The body weighs 30.00.

The density of a substanas je preimen ea

und volume e

The specific gravity of a substance is defined as

The ratio of the weight of any volume of it to the weigh

of an equal volume of water,

In F.PE oyatom, the unit of volume is in evicti

than 1 e-e, there will be two numerical values for its

Speiris gravity 18 a ratio, so the same Rumorient result to putaired whatever svatam or unter it "ard.

(b) -11) Brang Klycerine, gold, ather and mercury, with

their .G, greater than one, sink in watery d Till Jeep with 5.0, creater than 978 but lose then unity i

Floats in water but dinkes in alcohol.

iii) Gold, sinks in mercury since 5.0 of gold is greater.

h than that of gepry

(iv) Brass, gold and perfury

(V): Amber finets on BlycerinÉ ŠIS REPEUTY

Tol Hase of amply pacela

Heas of bottle when full or water.

Mais as water in it

62: 19:

Since the density of water is 1 km/s. the capacity the settle 18 25 5.27

Density of sulphuric acid

25 7 9 of sulphuric acid we lang 1:25 = 25 that

There7778, meer of poulle full of tuletuzte tald

The carbon dioxide 15 removed ov 50tution in water unger pressure,

A

The paqufacture of hydrogen is important because large quantijana are needed for use in the ganulactur amronia and hydrogen chlorice. It is also used large extent in converting vegetable oile to lats for margarine and cooking fat, and for hydrogenating to produse petrol.

(e) ina apparatus 16 set up as shown in the diagram, Initially the liquid levele in tubes A and B were at the same height Hydrogen diffuses put through the porous pot fasten than air diffuses in The pressure inside the porous pot faila and the water level rises in tube B and falls in tubo A

Hydrogen

porous pet

moaker:

(13.25 37.97 ga

It would hold 25 c.c, of alcohet, and weighs 65.56 zm. when full of sulphurig 6919.

・

415) *3-17-7-7- (477)

NTARJELAZRIFOR

FEJEKLARER 1 (841N5)

(1960, 8=-23.)

It a mixture of the two gases is exposed to diffused sunlight, the action takes place slowly, but if the mixture in exposed to direct sunlight or the light from a photographic flashbulb, the two gases WIL combine with explosive violence. A burning jet of - hydrogen wil1 however, burn quietly with a green. flame when lowered into chlorine,

Questions for next WÈNK

Three tvoes of natural water ara

1on (3).

(4) State the Princlude" of Archimedes.

a ar9se object and an aluminiup object are both totally Innerped 1 water and are found to have the same apparent weight Ho do their weight in air, and volumes, compare

A asker of Water le placed on a palanes pipA FERIBLATA 5289 818 CLORARY L Tuns on spring s balance and ls found to weigh 24 gm. When the spring balance is low- ered do that the stopper-ts gompletely laserged in the beaker of water (reeding falls to 15 go find t volume and specific gravity of the LORRAT. What new reading of the må ku ka lance?

6) What would be the effect on the barometer reading of

1 (1) using lightly, tapered barometer suber

(11) an incrsson in teepersture while the atomsphérD)

Teb) What are the ragters goleming the presenta AY MY MOUS

in a Liquid?

Describe an experiunm to show that thE REBELUM DEJAN The SurfLos At Liquid nervates with the PELA

Water

(d) (1) Hydrogen will reduce black copper oxide, to red metallic)

copper The action will take place if the oxide 15 heated

11) It hydrogen in bubbled through molten sulphur, the twe

Selegante undergo sherical combination, and sca)) auounts

of hydrogen sulphide will be formed."

1111/nydrogen, and chlorine willFresconto som nydrogenfenioride)

Starting with one of these types state priefly now you would

(a) remove temporary hardness only on serusic

(b) remove all the hardness;

(c) obtain water pure enough for chemical analysis,

2. Give one conclusive experimany to distinguish between?

(a) Chalk and anhydrous, soatum carbonate;

(b) washing soda and baking soda;

(c) spdium carbonate monohydrate and slaked line

3. (a) Ursoribe in detail the laboratory preparation of pure dry carbon gloxide from calcium carbonate, Callio Cabiche, (b) Describe tests to illustrate

(1) the density of the gee,

17(11) any three chemical properties

(c) A white substance A gave off water vapour and carbon dioxide

when heated After heating for a long period, a white residue was left which, when cold, evolved some more carbon dioxide on the addition of hydrochloric acid. What can you say about the chanical nature of A. Give reasons for your