阿教僑華
自三第張四第
日七初月三閏年牛丙春夏
WAH KIU YAT PC
三期星
日七十月四年六六九一曆公年五十五國民中
華
華僑教育
rrom the open pipr
rNz入
英中会考
化學科
三十七) 王錦釗
CHEMISTRY (17)
九六六年度
其中会題 試題預習專欄
*
九六六年度
I
物理科
(十七)
陸永熾•
{since the frequencies are equali
1.. * 70
5
PHYSICS (17)
By Mr. Luk Wine Chee.
[Let 1 be the length of sorometer wire
be the tension of wire with the stone hanging freely
Since
2
ม
f(frequency) X STension
400
immersed in water
2
S.G. of stone
{. weight of stane in air
wt. of stone in
wt. of stone in water
2
Ans.
-
S.G. of the stone is 2.78.
Since
Whe ri
{
Ans. The closed pipe is 49 cm. long
Let
1 be the length of each of these wira
N be the mass cer unit length
T1 Tension of wire *• 5 kg.H. - 5030 gm.wt.
=
Tension of wire B`- (5000 * 200) gm.w
2
1
frequency of wire A = 250
1
а B
门
•
圓
1.2" (1)
Ana. S beate per second..
frequency in c.0.9.
length of string in cœ.j
Tession in dyne
Let o
5200
* 2.50
5000
254.95
255 (3 &n
figures)
"
"be"the distance"apart)
t apoy be the time required sound to travel in air and
Ct - 2.65) sec. in water
2
# # 3.4 % 10 x t
1 mas per unit length in gol
3
'■ - 1.4 x 10' (t
2,65),
[1.4 x 10-16 -
103 (t - 2.55)
(2.65) * 3.4 x 30"
from squation (1)
2.1 (a) Sliver nitrate is usec in the laboratory to test for soluble
chlorides. When an aqueous solution of silver nitrate is
added to an aqueous solution of a enloride will be obtainen,, which is soluble in ammonium hydroxida, and insoluble is dilute nitric acid.
Ag* --C1
AgCl
(b) Ferrous sulphate is used in the laboratory in the brown
ring test for nitrates. Some freshly prepared ferrous sulphate is added to, a solution of a nitrate in a test-tube) and when a few drops of concentrated sulphuric acid are poured down the sides of the tube, a brown ring will be form the two liquid layers.
• H2504 2KN03
ZHMO
bFeSO 3H 250
*
NO, FeSOL
-
52504 * 2HNO3
Fe2(504) H20 + 2NO FeSO4·NO
c) Potassium iodide is used in the laboratory to test for the presence of chlorine. When chlorine gas in passed through- an aqueous solution of potassium iodide, the clean colourless solution turns brown immediately, as chlorine alsplaces iodine from putusele jodide.
CL2 • 2K1 -
(d) Ammonium hydroxide 16 used as a teel for soluble copper salță.
When ammonium hydroxide is added drop by drop to a solution of a copper salt, a pale blue precipitate if copper hydroxide As first formed, which is soluble in excess of ammonium hydroxide forming cupramonium sulphate.
+
Cu (OH)2 器
Cu(OH), +
+20H
(NH4)2 SUL
(*) Potassium ferricyanide is used in the laboratory to test for
the presence of soluble ferrous sails. When potassium ferricyanide is adova Lo a solution of a ferrous salt, a dark blue precipitate(Prussian blue) is obtained.
ff Lead acelate 19 used in the laboratory to test for the presence
of hydrogen sulphide When hydrogen sulphide 18 passed through an aqueous solution of lead accetate, a black orecipitate of leao sulphide is formed.
b (CH3C00)2
མ
Pbs
* 20H, CUOH 1.2 (a) (1) Pass each of the gases in tum through lime-water. Carbon
dioxide will turn lime-water milky, but nitrogen has no action
CO2 + Ca(OH)2 CaCO3, H2 O
→
(11) Put a piece of burning magnesium ribbon into a gus jar of each gos. The maggiesium will continue to Sum win some difficulty white ash, magnesium oxice, is obtained at the bottom of the gas jar, and black specks of carbon are formed
In the case of
2Mg: CO2
an the
*****
of nitrogen, the magiesium reacts with the ng to form a yellow powder, magnesium nitrioc, Mg3 a
when water is added to magnesium oxide, no gas is evilved. But when water is added to magnesium nitride, ammonia ly given off, which may be detected by its action on ittaus. Ammonia will tum red litmus bluem
6H20 5 Mg(OH)2
+ 2NH z (a) (1) Put a Rebly glowing splinter into a gas jar of each
gas. Oxygen will rekindle the glowing splinter, but nitrous oxide will not
MENZ
=
(11) Put a gas Jar of nitric oxide mouth to mouth with s
ges jar of the two gases Oxygen will give brown fumes of nitrogen tetroxide with nitric oxide, but nitrous oxide hap, no action with nitric oxide.
2NO • 02
$20
En aqustion (2])
102 (24 - 3.6)t_= 2.65 x 14 x 10)
10.6 -- 2.65.14
(e) (1) Allow a test-tube of each gas to mix with some air,
shen both mixtures are ignited, the mixture of nydrogen and air will-burn-explosively giving the familiar "pop" sound while "the mixture of carbon monoxide and air will bura quietly,
1
242
200 + 02. ❤
2420
2002
R
• 7.8 %
Cann. Tansion
• 65′′ × 1,0 x 2.7.1 i slo
- 7.7 x 10 gm,kt....
'K 2702 EMAI
of the string is 7.7 x 10” gm.wt.”).
Closed pipe (3rd overtone)
Open pipe (4th overtone)
Let 1 be the length of the closed pipe
be thei
wave length:
be the velocity of sound.
length of the open pips
70 om.
From the
sed pipe,
I
認會計師公會之批准。
師公立登記,並參加政公會之发强考
一,由今年九月起,工興學院之全日青村学
工專會計學課程 已獲倫敦公認會計師公會批准 (轉筋)教育司昨日(星期二):文架
由兩年改爲三年
凡些習的課程之學生,將由公四會計
-此爲期11年之于镞務,已獲得倫敦公
母年亦收塔新生一千很大的利益 |
(19)
the explosion is 1.19 & 202
(11) Pass each gas turn into two test-tubes
ach containing an ammoniacal solution of cuprous chloride, carbori mariowide will be absorbed while hydrogen will pass
hrough.
1. (8) Give a labelled diagram of an electroscope and show
how you would use it (1) to find the sign of the charge on a given Insulated conductor, (ii) to find which of the two conductors has the greater amount of charge.
(b)what is meant by the terme magnetic meridian, magnetic
declination magnetic dio?""
Describe briefly how you would measure the angle of dip Cand declination.
2. ABC is a triangle of three resistors and AB - 4 ohms,
BC - 5 ohms, CA - 6 ohms. If a current of 25 amp, enters at kand leaves at C, what is (a) the current in 30, (b) the P.D. between Band.C7
3. Three similar cells, each of internal resistance 0.4 otim, pro- duce the same current when they are connected to a certain resistor in series or in parallel, What is the value of the resistor?
4. (a) A TÚ k-w dynamo generates at 200 volta. The current from
the dynamo passes through a cable of resistance 0.5 otuas Find the fall in potential along the cable, and the Dower loss in the cable.
(b) As in part (a) but the dynamo generates at 2300 volts.
5. An ammeter, of resistance, U. 3 ona, can measure currents up!
to lamp. (a) What shunt must be used to enable the ammeter to meas
currents up to 5 amp.?
((b) What is the combined resistance of the ammeter and ne
虢州學院備處,並
假都子-
體有要助
生開如薬草當助人處先篇可洲學常用品钦因米
雜果:金開然,士,成能由基院費,會收和且能如屬控府此,
新足健府
私學
願分子以府,瑞分此。取助
交校校
時人,願爲願申
备
CuC1.CO1H20
HCI 1.35.3
- 36.5
MaON 23+16+1
40
NaCl + H20
- 30.5
* 18.75 21. of
x
• 0.075N
The aquivalent weight of HC1
.... H&O
25 ml of NaOH solution
(the norosity or solution is to
(a)
and the concentration of NaOH solution (40 x 0.075) gms per litre
- 3 gme per litre
kt. of pure NaOH that will dissolve in 250 ml of water.
wt. of sample
雠, of water in the sample Harice of water in the szenis
Questions for next week
1
-0.75 gas
• 0.90 g
- 0.15 got
0.15
0:22 × 100 %)
0.9
168
A
......
0.1 What is the difference between temporary and permanent hardnear of water ? Name and give the formula of one compound which causes each type of hardness
Write equai long to show how (a): slaked line, (b) washing.
ends may be used to soften hard water
50 ml. of each of three samples of water (1) distilled, (11) tap, (iii) boiled tap, were titruten with soap solution, and required respectively, 1.5 20.4. ana 10.5ml. on the
Find the ratio of latter to form a permanent latter. temporary to permanent hardness in tap.water
0.2 Indicate briefly the, reactions you would carry out in order
to obtain samples of (a) chlorine from potays thin chlorate (c) lead from lead nitrate, (a) suldur fram nydrogen sulphide, (e) lime-water from limestone.
0.3 Explain what is meant by ta) a catalyst, (b) un equilibrium
mixture. Give an account of a large-scale process involving a reversive reaction 17 which a catalyst is useo, naming the catalyst and explain why it must be used in that reaction...
服,以儀件驗酿酒 進學常的有必評定
務應故及事
有救
·件學翔。
【费
̇餸菜
particular:
區教師 上午爲九龍區教師 下午為新界
定在籍試完,成後,中學報在十八日第
評定後,饟試及格酒 行, 資格 黑六小時,誤段包括
【湛教師試,下午一班之小學組,已經在克 綁死的入學試,依規加者有一百五十七,别跟亦暫定低调上
·爲新界教師口試。 本月十四日及十五日 · 太原維訓班的學 投考在啟激師訓 两天银行,獲资格 制,仍於两年,學員 下午舉行,上午爲九 古方面,富國 斑得通知,九月入那 ,將於五月二日分上日行就完驶,至萬選著約在八月 【创研班入學試之日芑 各區跡於上月廿八 作录綠之眾蝕决定, 【區及新界區在亞汝航 閲標班的入學考时,口試後,仍有待發影
• 葛量洪猁範學校九龍,本年度在晚致師入學試考生,在經過 C轵♪本年度「硬核。在放鲡綳娩证
格得行八區十1根一行四
,加項及,人在
宥慈考千亦,韬
必須再參加試,此若有六十餘人,至於 中文、英文、
光电
組敎師主持,脫查 四十餘人。經。八成
,然就得音
、腰及
破不多,因為一個一個數目,已經底亞 一區薪的熱狄裡的,案 左右的浪費,超過道 經費,名 備,及,大概永年月二百元 入。但大惠方面、熊 中童考取賜生牙藏家 中文大學所收學生「本致臂」有一大 一定限額,約有千餘。本人覺得在本来高 「餘人。但香满大學應,过可能對本港「* 【人?中文中學有七千青界人士去發組熱織 中會考有一萬九千餘發生那爆。可找些学 多棋女性約,今年中能够注意到,或者 學會考畢業生,河許的柱港代表白安椅 於本港年中英文中,希望 金會 麦黑鸟,降餘如下,大人旅含首要。目前 王氏炳-本人閣 本人不過提出一項寳 前往訪問,請王氏發 髙杀? 教育和商科 橋洲基金會在潴发 生命一千個境會。 | 以英文校聯會副食品的人數。翻志說- 主当利,昨會發表團升學年可協助會考基 此馐,奔港商業電台 港大和中大两校所收 生之升學及學後分配 道緤它所倍校約等於 之後,有國高中時,可以收摊班生。
希望會駐港代表感興趣
大談亞洲學院
商台訪王幸利
【
安,及經常費用,相實族,因而一間民
一般不易支持。因此,亞洲學院,廉欤學幾
當浩大,非有-
足強基倫會協助成立的
九龍及新界區師訓班
定五月二日口試
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