1969-03-05 — Page 22

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1969 文中學會考試題預習

日橋

三期星日五月三年九六九一番公年八十五國民華中有教僑華

三九六九平中文中学会試題殖器つ

0.20 2Na ZHO 2 OH

2NaOH

2HC12No012850

化學科

英文科 (十八)

王淑方·

(十七) 王錦釗

From the above equati ns.

we can see that,

CHEMISTRY (17)

A solution containg P5′′ and Ag ions, Heat and HC1-

are available to test the solution. The two ions

could be distinguished because

AgCl la insoluble, PbCl is not

B PbCl is insoluble, AgCÍ is not

C AgC1 turns red on heating.

D PoCl2 18 soluble in boiling water

E. Ag01 is soluble in boiling water

2. 0.02 gram equivalent of sodium is added to water,

and when the sodium nas reacted completely, 15.0 ml of N HCl is soded. To make the solution deutral, it is now necessary to add

A 0.13 gram equivalent of sodium

85.0 glor Naoddum nydroxide solution

50.0 ml of 0.1 M HCl solution

D 5.0 ml of 0.1 M HCl solution

& 300 ml of 0.2 N nydroxide solution

An element X has 6 electrons in its outermost she11.

It probably will

form positive ions

B form negative ions

C be inert

D be relatively unreactive

5 be neutral in solution

When a dilute solution of hydrochloric acid is heated, the vapour evolved contains".

A pure mydrogen chloride because it has a lower

boiling point

..

a mixture with the same concentration as the solution

a mixture with a higher concentration of hydrogen chloride than the solution,

a mixture with a lower concentration of nydrogen chloride than the solution

metal nydroxide is insoluble in water. It does not dissolve in caustic soda solution but is soluble in ammonia solution. The nydroxade. 13

aluminium nydroxide

Lead nydroxide

ferric nydroxide

sine nydroxIDO

E copper hydroxide

In separate tests, each of the reagents listed

below is added to a solution containing Cu2 and

Lone, which reagent would give a precipitate each case?·

hydroonloric acid

excess aminonda

södžum hydroxide

hydrogen sulphide

B sulphuric acid

A solution that, on the addition of sodium

nydrazide solution, gives a white precipitate which subsequently reacts with excess reagent to leave a clear solution

must contain

b

could contain Cr“.

will not contain A13

D could contain Zn-

contains all the ions Zn,

and Pb

The main products from the incomplete combustich

hydrogen sulphide are

nydrogen and sulphur

nydrogen and sulphur dioxide

water and sulphur

water and sulphur dioxide

sulphuric acid,

When chlorine reacts with a cold dilute soluble nydroxide other than ammonium hydroxide it forma

perchlorate tona on ly

chloride ions only

chicrate ions

chloride and chlorate ions":

chloride and nypochlorite ions

10. In the reduction of two axides of a metal, 12.8 grams of one oxide yielded 8 grams of the metal, while with the other, 19.2 grams yielded 12 grams the metal. These figuras illustrate

A law or constant proportions

B law of multiple proportiona

Cno particular law

D Gay-Lussaç's Law

Law of conservation of matter

11. Methylated spirits consists of

A methyl alcohol and ethyl alcohol (50% approx.)

B methyl alcohol with a little ethyl alcohol

C ethyl alcohol, with a little methyl alcohol

D the two alcohols and water

E glycerol and methyl alcohol

12. In the Ammonia-Soda Procese, the NaHCO3 may be

separated from the other products because

A heat readily converts it to sodium carbona

B it is the least soluble of the products

▸ the other products are all insoluble

Dit is the only acid salt formed

E it doesn't react with the brine

SOLUTION

CID Both Pb and Ag

hydrochloric acid

Pb2 201

Ag+

ions give a white ppt.

PbCl2

However, Lead chloride is soluble in boiling) water while silver chloride is not,

1 gram equivalent of Ma = 1 litre of M Hol

1 gram equivalent of HO1)

15. m. of N-801 = 0.015 litre of N-HC1

= 0.015 gran equivalent of hol

bihan 0.02 gram equivalent of sodium is added to this acid solution, there will be 0.005 gram equivalent of sodium in excess.

In order to neutralise the excess alkali, t of hcl required. 0.005 gm-equivalent Vol, of -01 required 0.005 litre.

of

10

(2)

required 0.05 litre.

-50 ml

Q.3 8 The element will probably form compounds by

accepting two electrons from some other element or ion in order to acquire 8 electrons in its outermost shell. When it will then have the electronic configuration of an inert gas, such as neon or argon. The resulting particle will be

negative ion.

Ze

When dilute hydrochloric acid is heated, both water vapour and hydrogen chloride are driven off and the acid solution becomes more concentrated, until a concentration of 20.2% is reached. At this point the acid solution boila at a fixed temperature and is called a constant boiling mixture. The vapour given off when dilute acid is heated is richer in water vapour than hydrogen chloride.

4.5 & The metallic hydroxide mist not be amphoteric. The hydroxides of aluminium, lead and zinc are amphoteric and will dissolve in caustic soda solution to form salts.

Zn(OH)2 + 2NaOH » Na 2002 • 2H,0

sodium zincate

This leaves ferric and copper hydroxide. Ferrio hydroxide is insoluble in alkalis Copper hydroxide will dissolve in ammonia solution forming a complex ion.

Cu

Q.5

4.7

Hydrochloric acid does not form precipita tes with Cu” and Ba** long as both copper and barium chlorides are soluble in water with excess. ammonia, copper forms a complax ion, while barium hydroxide is sparingly soluble in water:

Caustic soda will give a precipitate with both ions. Both hydroxides formed are insolubla in excess.

201"

201

CULOH)2 V

Ba(OH)2 only sparingly ad1vhla

With H 3.Ba? forms a soluble sulphide although

copper sulphide is insoluble,

with H250 Bạc forms an insoluble sulphate but copper sulphate is soluble.

The solution first gives a white precipitate of the metallic hydroxide. If this metallic hydroxide is soluble in excess caustic soda, the metallic hydroxide must be amphoterie nat 18, the solution gould contain all the tons

A1 and Post

4.8.0 When hydrogen sulphide is hunt in a limited

supply of air, the following reaction takes place

28

02-220

4.98 when chlorine is passed into a cold dilute

solution of caustic soda, the following reaction takes place

0.11

C12 2NaOH - NaCl

NaC10

that is, chloride (C1") and hypochloritë (010) ions are formed.

Weight of oxide

Nt. of metal, after reduction of the öxide

by weight of

the metal in the Oxide

1st uxide

12 8 gms

2nd loe

#82.5%

* 100%

192

Hence these figures 1llustrate the Law Constant Proportiona

Methylated spirits is a nature consisting mainly of thyl alcundi with seller als of ethyl alconol and water-

Q. B The ammonia soda Process depends upon the

fact that sudium bicarbonate is unly slightly soluble in water, and may be considered to be insoluble in brine

Questions for next week.

hext week, we will again examine a number of multiple choice questions covering the chemistry course as a whole

LESSON EIGHTEEN

SECTION THREE

ENGLISH LANGUAGE

COMPREHENSION

EXERCISE 26

Read the following passage carefully and then answer the questions that follows

We got out at Sonning, and went for a walk round the village. It is the most fairy-like little nook on the whole river. It is more like a stage village than one built of bricks and mortar. Every house is smother- ed in roses, and now, in early June, they were bursing. forth in clouds of dainty splendour. If you stop at

It 18 Sonning, put up at the Bull, behind the church.

a veritable picture of an old country inn, with green. square courtyard in front, where, on seats beneath the trees, the old men group of an evening to drink their ale and gossip over village politics; with low, quaint, rooms and latticed windows, and awkward stairs and

winding passages

We roamed about sweet Sonning for an hour or so, and then, it being too late to push on past Reading, we decided to go back to one of the Shiplake islands, and put up there for the night. It was still early. when we got settled, and George said that, as we had plenty of

of time, it would be a splendid oppor tum ry to try a good slap-up supper. He said he would show us what could be done up the river in the way of cooking, and suggested that, with the vegetables and the re- mains of the cold beef and general odds and ends, we should make an Irish stew.

(Three Men in a Boat- Lerome)

(1). For each of the following fand a word of sama tar

meaning IN THE PASSAGE:

stayed

(6) delicate

(f) beer (B) chance

talk idly

(c) rambled or wandered about (h)

(d) real, actual

(e) covered

Where is Sonning situated?

secluded corner

Why is the village more like a stage one than one

built of bricks and mortar?

(4) When did the author and his companions visit Son

6)

(7) (8)

Why does the author advise people to put up at the Bull in Sonning?

For how long did they wandered about the village? Where were they going to put up for the night? Why did George decide to make a stew?

EXERCISE 27

Read the following passage carefully and answer all the questions:

It was a strange ceremony. A pit-tailed twelve- vear-old girl standing at the top of a hall formed a cup of her hands. Then, aiming her words to the vast open space between herself and the peaks in the dis- tance, she yelled out in German: "Orphans of the worla, wherever you are, come. Welcome you here!"

She had been facing East as she spoke. Now she turned South, repeating the words in Italian, then West and North in French and English..

Around her stood 185 brightly-dressed children ranging in age from 4 to 18. Their cheeks were flush ed and they were obviously enthralled by the simple ceremony. To them it had great significance for they were celebrating the founding of a Children's village in Switzerland..

There was good reason for the ceremony. Only short time before, these happy, healthy youngsters had been half-starved and emotionally upset. Innocent victims of World War II, rescued from burning ruins and crumbling houses throughout Europe, their families dead or among the countless missing, they were suddenly transplanted into a world which must have seemed ag fantastic and unreal to them as Wonderland appeared to Alice.

These miserable tittle creatures had never lived a normal life. To them, houses with roofs and windows with glass were unreals and it was strange indeed to the inhabitants of this village to spend their nights sleeping instead of urining from shelter to cave and cave to shelter, to p protect themselves from bombs. snipers and thieves.

Now, eight years afterwards, with their war scarg healed and their basic education completed, the first growing generation fo the village graduates has already taken its place as useful citizens of the countries to which they belong. Having been cared for with love and understanding, these former victims of hatred and pre- judice are returning to their respective homelands to spread the message of tolerance and they sow the seeds of a better future.

(1) For each of the following words give another word

which

(a)

Ne used to replace it in the passage:

(b) enthralled

(c) significance

(d) founding

(e) voungsters

(£) transplanted.

(g) fantastic (h) basic

(1) prejudice ()tolerance'

(2) (a) What was the reason for ceremony?

N.B.

(b) What kind of children feel they were chosen

to live in the village?

(c) Why did the children feel they had entered

Wonderland?

(d) In what way was the education of the Village

children meant to fit them for life after they had left the village?

ANSWERS to EXERCISES 24, 25, 26 and 27 will os given in next LESSON.