1987-03-09 — Page 24

育教聞港 ~

頁三第張六第

WAH KIU YAT PO

報日僑華

日十初月二年卯丁曆夏

推育 體出 會方敬敬 要同基 的面艇鍊 放學在

會長良運

一發全導總插市,劳馬校長鄭德健。

·保良局第一中學運動會,陳鴻基主席 继心和意志力,帮助同 光威理- 以防蟲害。」 育活動,培養學生的自動场,因此必須經殺

體育活動,希望透過體面、花園、遊樂場及運

,用以帶載泥土及植物,

健陳

方長 運重 衡健多好崀 波斯 變壓,體加力禮高 化力將線 體求致: 來,寶學詞中

寇,配社逐、按 游綠學 軍程塑榮

獲了全,芬 女船場送發成 拿 子團總 前與紅悭。 組體感佳色,賽

雞 綠

動

·

進

獎

導致適而使活外,席 寄總官般送鼓事

應對身簿,微仰 體冠,

就各心,更勵高,德軍黃紅頭黃全

到蟲

【或處

沿用六

可堅摩

2 K

九之乘竹

良局研主席鞬再基及枕 運動代鱼在降

運動協舉行陸運會,保心克服困難。

一中學三月五日假沙田,將來在社會工作有信 _〔港讯)保良局第一學應付功課和考試壓力

保良局一中運動會

陳鴻基副主席頒獎

市局購新竹籮

一期星

日九月三年七八九一曆公年六十七國民華中

士」高级音响器材。「絕,場面轟動,好評如 月「代理之品——「山水大以來,來自國內 」,「先錢」及「張各地之參觀人上格繹不一 紅,出和岩常業集團「視聽展八士」 年[禀李永森及廣東省商業|亙作詳盡示裢講解,深 長到水就主持剪 愛國內人士們賞。

▲ 五日,在廣州市病津東出卓越優秀的視器科技, 日前由和市造業集團主塲產品更由專業技術人 |路商業貿易中心舉行,及新美觀的設計,係 「辦之「視聽展八七」,明器材,「先鋒」靚 日於二月十八日至三月器材等,各猳產品都顯, 一國人員服務公司聯合主聰器材,「馬關上」香 | 貿易中心,與廣東省出 接收系統,「山水」說 電業集團,廣東省商業 錄音帶,DX碼港維 [港訊〕香港和記 },其中包括 T HATS.

和記電業集團

本港 新 與國內單位辦

「視聽展八七」

̧屁品肄式風羅棋佈

〔為「與八七」剪綵之情况。)

1987中學會考 試題預習專欄

化學(廿四)

明邋出版社

MILL & DALE PRESS

Revision Exercises

for

Cert. Exam. (1987)

CHEMISTRY (24)

Answer to Questions 34 (a)

(i)

The litmus paper would remain unchanged.

(ii) It is because the

solution X does not

consist of any mobile ions as HC1 still exists na .covalent molecules.

(iii)White precipitate of

ammonium chloride- would be seen, This i's because ammonium chloride, being ionic in nature, does not dissolve in methyl benzene which is covalent (iv) The electronic

structure of

ammonium chloride is as shown below.

1987中學會考 試題預習專欄

物理(廿四)

明連出版社

-MILL & DALE PRESS

Revision Exercises

for

Cert. Exam. (1987)

PHYSICS (24):

(24)

Domestic electricity.

Mains cable contains

3 wires'; alive, a neutral

and an earth wire, The

colour code for these wires are brown for live (L), blue for neutral (N) and yellow and

(earth (E).

freen for

For household appliance the earth wire should be connected to the case (metal case) and the live wire should be connected to the ON-OFF switcb. The following diagram shows

how a household appliance

is connected.

heater

ON-OFF switch

Example:

نبه ۹۷۸ ۹۷ است نیز

socket

house bold appliance

(a) As shown in the figure,

6A

fuse.

box

a electric circuit for

a kitchen consiata of

a lighting unit:

(2007, 200w) and a cooling system for refrigirator (200V, 8W).

lighting".

unit

200 V

cooling

system

&

O

Key: electrons of

nitrogen

electrons of chlorine

electrons of

hydrogen

They are ethene for

any other gases

alkene), eulpintr

dioxide and hydrogen sulphide.

(ii) Gás X is expected Vol

be sulphur dioxide.

(iii)The equation is:

BAC12+S02+H¿0

BBSG, (8) + 2HC1 (c)Maas of 720 cm3 af

ges 2.

of)

mass of mass of solid residue.

-0.45-1.49

-0.96 g

mags of 1 mol of gas z

-0.96x

24000 720

328 *.M(7) is 32,

Answer to Questions 35

(i) As read from the

graph X and Y have the same solubility` at 90°C and the value is 50 g. (ii) They are 27 g at

70°C and 9 g at 30

(i)

Find the maximum

current drawn from

the mains.

(ii) If a ÓA fuse is used in the fuse box,

will the fuse blow?

(iii) If electricity cost 60 per kun and the whole kitchen is in

full use for 10 hours

everyday. What will

be the cost of.

electricity for one

month (30 days)..

(b) It now a heating unit (2009, 700W) is added. to the kitchen by connecting in parallel with the lighting. unit and cooling system, as shown in the figure below.

Ба fuge box

lighting unit

cooling

system

beating.

unit

switch

$

What happens, if all appliances are evitched on. Explain briefly, Solution:

(a)

or

Using

P. IV

I'm

Current through light unit

-1A

200 200 Current through cooling system

800

4A

200

.Maximum current

drawn

1A+A

- 5A

(Ans.)

(ii) No, for the maximum

current is smaller.

than UA.

(iii)Energy consumed each.

day

(5)(200)x(10) wh

e 10 kih Energy consumed each

montb

10x30

300 kwb

3

Cost for the month

(300)x0.6

(Ans.) $180 (b) If the heating unit is

switched un, current through the heating unit is given by

respectively.

(iii)at 70°c, 100 g of

water dissolves 27 g of Y to from 127 g. of e saturated solution.

But, at 30°C, 100 g

of water only. dissolves 9 g of v. Thus, when 127 g of saturated solution of Yat 70°c is cooled to 30°c, (27-9)-18 g of crystals of Y would be formed,

,mass of Y that would

be obtained on cooling 50 g of solution saturated of Y at 70°c to 30°c

50 *180*127 -7.09 g

(iv) Mass of water =(120-45) -75 g

Solubility of X at 40°C is 38 g.. maximum amount of X that dissolves in 75 g of water st 40°C

75 100

=28.5

deposited

the salubility of X is. 38g and that of Y is 38 g

Which is much larger than 6A aud thus the fuse will blow. Example:

(a) A Lamp A marked "6v"; 12W in connected in series within 10 resistor and a by battery. Assume the internal resistance of the battery and the resistance of wire

are negligible.

6V

6V,12W

Find (i) the current

hrough lamp

The pover Sdissipated

by A

(iii)explain

briefly why

the pover

dissipated in

not equal to.

12W as marked

on the lamp.

(b) If a laup B, marked by

12V. 12W is inserted between the 1

resistor and lamp A

as shown in figure. below,

ÚV

12v,12W

6V, 12W

(i) Which lamp is

brighter? Why? (ii) If now laup A is

taken away, would lomp B brighter. than lamp A. in part (a)? Why?

Solution: (a)

(i) Resistance of

12

30.

Current through lamp

6

1+3.* 1.5A (Ans.} (ii) Power dissipated by A

- (1.5)2(3)

(Ans.)

- 6.75 W

(iii)P.d. across lamp A

* (1.5)(3)

4.5V

700

-

3.5A

200

Total current drawn

8

from the maina

5A+3.5A

8.5A

Since the voltage across lamp A is less than 6V, therefore the power dissipated is not equal to 12W as marked on A.

Realstance of B

(ii)

maximum base of A

that dissolves in

50 g of water at 40°C

50

-38×100 =19 g

and, maximum maas of X that dissolves in

50 g of water at 40°C

50

=12X100 =6 g

the mixture orginally contains 15. g of X- and 15 g of Y.

11 X is dissolved but (15-6)=9, of Y remains undissolved.

X is propan-1-01 (It cannot be propan-2-01 because on oxidization, it would give a ketone instead of an alkanoic acid).

A is propene.

B is propanoic acid;

C is 1-chloropropane.

D is propyl

ethanoate.

11) Conc I50 is used

and heat has to be applied.

CHSCH

(2) Acidified potassium

dichromate (or potassium permanganate). i a used and hent has to be applied. CHCH2 CR2OH+2(0)

CHCHCOOH+H2O

12078

Since A and B are

connected in series

Power dissipated in A Power dissipated-- in B

;

1. :

312

4.

B will be brighter. (ii) Lamp B will be

brighter than that. of lamp A in part (a), it is because resistance of B compared with the 1n resistor is much higher than that of. resistance of A compared with the in resistor. Thus the energy loss.

dissipated in the in esistor is smaller than that in part (a).

經濟(廿四)

明逃出版社

MILL & DALE PRESS

Revision Exercises

for

Cert. Exam. (1987)

ECONOMICS (24)

Public Finance Distinguish between direct taxes and indirect taxes so as to show their advantages. Give local examples of each. What would be the probable economic consequences if beavier taxation is composed to Hong Kong?

A direct tux is the taxation which is paid directly by individuals or companies on whom it. is actually levied. The tax burden is exactly bare by the tax payers and the tax is levied on the taxable income of the individuals or companies, Examples of the direct taxes are the Salaries Tax, Profits Tax, Property tax, Interest Tax, Estate Duty, Licences Fees and Rate in Hong Kong.

The Salary Tax is charged on any individual who is in receipt of income from any employ- ment in Hong Kong. It is charged on a sliding scale from 5% to 25%, using the progressive tox rate. The taxable income is derived after deduction of various allowances which vary with the individual and family circumstances.

(3) Phosphorus(V).

chloride (or

(iv)

phosphorus(111) chloride) is used and the reaction would take place at room temperature.

CICH CH2+PC15

CHCH2CH2C1+

POCI+HC1

(1) It is the additiou- polymerization.

2) Y is polypropene.

8

CHCH-CH2 C

C

Answer to Questions 36

8

Nitrogen is obtained from air by. fractional. distillation of liquid air. Hydrogen is obtained from water by electrolysis of Ecidulated water. The yield of NH¬ would be incrsused by using a low temperature. Since the forward reaction is exothermte so,

a low temperature will shift the equilibrium pusition to the right.

Profits Tax is charged on any profits derived from the trade and business in Hong Kong The standard tax rate of a corporation is 18.5% where the unincorporated

baa is a standard-

of 17%.

Interest Tax is charged at the standard rate of 17% on interest arising in or derived from Rong Kong. It is the tax which levied on the interest derived from any debenture, mortgage, bill of sale, deposit, loan advance or other indebt- edness.

f

Property Taxa charged at the standard rate of 17% on 80% of the accessable current market rental value. Every owner with property in Tong Kong is necessary to pay

mount of payment.. Besides, Estate Duty

is the duty imposed in a dead person's property, money or estate. Licence Fees is levied on all

business except the non- profit making business and some charitable organizations Rate is charged as a certain percentage of the estimate yearly letting value of land or a property held or occupied. by a person.

An indirect tax is the taxation which levied on goods and services. It is usually levied on expenditure.

Examples of the indirect taxation in Hong Kong are the Custom Duties, Excise Duty, Betting Duty, Stemp Duty, Entertainment Tax and Hotel Accommodation Tax.

Custom Duties are the taxes which are charged

six groups of imported commodities alchoholic liquors, tobacco, certain hydro- carbon oils, methyl alcohol, certain non- spirit drinks and cosmetics.

Op

the Excise Duties are taxes which charged the above six groups of locally manufactured commodities.

Stamp Duty is modelled on the British system which imposes fixed duty on certain classes of documents and an advalorem duty on others. Betting Duty is the duty on Horse betting and on cash sweep contribu- tion. The operation of Betting Duty is solely Gonducted by the Royal Rong Kong Jockey Club.

(iii)The yield

of Nll, is

favoured by using a high pressure. Since the number of moles of gasenus reactanta is greater than that of the gaseous

pruduct, so a high pressure will shift the equilibrium position to the right,

(iv) According to the

equation

Jnol 2mol

1mol ?mol

ammount of NH

mol

The ammonia can be separated from the mixture by

dissolving it in water (or directly in a dilute acid for making the. fertilizers.).

(2) They are dried and

used again.

(vi) A suitable catalyst

is iron powder. (vii)% of nitrogen in

(NH), 50%

2x14

130*100

21.21

% of nitrogen is NOND

14

x100=1647

Thus, ammonium sulphate is the Banides, the: Entertainment Tax is charged on the prices of: admission to race meetings and cinemas. The Hotel Accommodation Tax is imposed on hotal and guest houses. The cage sto Royalties and Concession are payment which the government received from public utility companies such as bus company, electric company, etc. which enjoy monoplistic franchises.

Compared direct taxation with indirect taxation, several distinctions can be

drawn:

(1)Direct taxation is

levied on wealth and income where indirect taxation is levied on expenditure. (2)Direct taxes are

usually charged by the government. The taxes are directly paid by the tax payers to the Gov't. Indirect taxes are usually borne by the consumers and are not paid by themselves directly to the government but through. somebody else. (3)Direct taxes are based

on the Ability-To-Pay Principle. It means. that people should be taxed according to their income level. The higher income group should pay more Indirect taxes are justified by the Benefit Principle, It means that those who get satisfaction by "consuming goods. and services should be taxed accordingly. (4)The imidence of

indirect tax may be on the buyer or seller, depending on the elasticity of demand of the commodity on which the tax has been imposed. If the commodity la more elastic, the tax burden would be easily shifted to the buyer. It is easier to deter- mine the incidence of

a direct tax but it is difficult to determine the incidence

of an indirect tax especially when the taxed goods are elastic in demand.

the

(5) Indirect taxes are

asually regressive. If all people conaume

taxed commodity in similar amount. The proportion of tax to income is mucts higher for the lower income

group. (6)Direct taxes are

generally in progres-

8

cheaper source.

A is sodium bromide. Bis hydrogen.

bromide.

cis iron(III)

bromide.

(anhydrous)

Dis hydrogen gas. (ii) Concentrated

sulphuric acid is used.

+Hkr

(iii)Sodium chloride is

also formed.

+2Br 2017.

17+ B*2

(iv) The flume is pale

blue in colour.

(v) At the anode.

chlorine gas is liberated 2c1

At the cathode hydrogen gas is liberated

2H+

(vi) Bromine atom has 7

electrons in the outermost shell, 0, the bromine molecule has the following electronic structure.

оо

(vii)Chlorine has a

stronger oxidizing power because it has a stronger affinity for electron than bromine.

sive tax rate. It is said that indirect taxes can widen the gap between the rich and the poor people with Large families. Therefore, direct tax con achieve more even distribution of wealth In the economy. (7)Direct tax can

directly influence the income and individual or a family. Since more taxes are required to pay in respect to higher income, it may.. discourage individuals from spending or Beeking additional income.

(8)It is easier to

estimate the amount of revenue that can be collected from direct taxes. It is difficult to compute the exact amount that would be yield by the indirect taxes.

(9)Direct taxes may Cause harm to the working incentive, investment Pacentive and the

Baving incentive of the firms and individuels.

(10)Tax evasion and tax

avoidance are more: frequent and much easier for indirect taxes. Hence, the administration cost of indirect taxes is relatively heavier than of direct taxes.

The following are the probable economic consequences of imposing heavier taxation in Hong Kong:

1. High salariés tax

reduces taxpayers' disposable income for consumption, and discourage peoples! Incentives to work overtime and to seek for promotion.

2. Heavier profit tax

reduces businessmen's savings and net profits. Loanable funds in the economy

will fall, and

investment become s 'expensive. Economic

activities wil) shrink as a result...

3. Heavier indirect taxes

would lead to rise in prices of necessities. Thus it results in inflation which cause harm to the competitiveness of Hong Kong'a exports. 4. In general, heavier toxation leads to greater governdent revenue, but

discourage foreigh investment flowing to Hong Kong.