1973-12-15 — Page 16

展工育教

日五十月二十年三七九一膳公年二十六国民華中

報日僑華

六期星

WAH KIU YAT PO

臨

黃四第張四第日一廿月一十年丑癸屬夏

·工展售舞表演警犬(記者)

工業安全防火第一

應防

防火專家陳典列舉工廠防火的設備措施

廠員工應具備知識

防火專家陳典氏近照

:吷起市民有所認識。 分析有關現下載苦通的越过防火器的使用, 此

·各類防火器材之東興紡製造負俺人陳典氏,予

·工作犀角落當眼處,以便】旦發生大火警時 安有火筒及防火屁啊,它所安置地方是梯間及

·鲽氏首先解釋目前工廠之防火器材,大都是

致手足無措 形成一發不可收拾。 n.

.從上述所損失數字中。據網查所得,以工業 救火的技術沒有-

份了解。更沒有鎮靜從事, 多採用該類防火盛,它分有四1;确至五十磅多種

之財產展生命之銦-實令人觸目驚心。......尺左右。 :,此外,當火,一旦發生之後。耐防火常識和 航空公司、飛機塲、飛機庫、 製造廠等地方, 一,相信可以減少許極火警發生,無謂的抵失亦可力亦特别强-並能透沌燃烧物過時,迅速而商實 | 當的放置,假若市民程常忧於後那方面時加据防,能隔絕其所需之助燃氧氣 - 氣並不受阻障,噴射 惹火物如天那水-油 火水 石油氣等沒有油,由於它比空氣還重,如在箱罩游戲境中的物品。 | 鼎將所發出的帶定,燒針時所發出的火花,易燃類防火器,使用時衹要將製Ÿ 按 - 便有氣蜓噴出 失火佔主要,而工業失火的起因,大部份是市民之安化炭氣體。是目前各類滅火筒市最强力的一 九百二十多人受傷,從過去十11個月來火警損失 下“使有染液喚出。通常射程約一十五尺至三十 八百多處元。此外,有八十三人因火警而形亡。 審任何物料。亦不會傷挞皮牌,詆要將蓋頂誤拍 千六百八十多宗,損失財產金线,約有一億五千,不適宜驭射孢類火燄,同時,該類滅火器不會揖 本年逛]三月卅一日。本港所發生火警數字,共六值適宜一股棉花,布疋。紙張,木材之類火警, 根津最近有關方面公佈。由去年四月一日至,其性質大致與上述一楂相同,但水劑的滅火器。 -目前本潴一般石油工程公司,發泡起質工廠,

梳打酸水混合,該種滅火器亦是轉向四殓噴射 :::至於另一種CO2氣 最新水型滅火箭,恭用 當使用踦祗要從四遁色 噴射,火能月然 繳 另一裇是CO2火,它是一種噴射壓縮

油的獒液及粉末,一經混和,即可形成泡沫射出 內及一切的油類火燄,使用時秕要將筒倒置,而 相適用於撲滅一般電油火燄,天那水,燃油,煤

部

晚響

親表方

位攤察警場會

精演表犬警

均

火勇

、

毫關

猛

的

的

在

行有

八特》一九四九年間

日本藏初成立要大致之時!

牧羊大,其所担任的職實

亦限於邊防的巡遍。

∴ 爲進一步使本港市民對

| 器材的運用及其性能,日前會往訪本禳專門型造.治。向火神挑戰,遊走火魔,願大家团最。 :,無可否隗,近年來本港消仿待,對工業防火··· 最後陳氏呼籲全港市民小心防火,因目前火一吃果行的大技能的表演。 因此,爲了使市民有明瞭自前本港各類被火,日常不小心所引致,希望全港市民要預防勝於獠,飛經地區則難道歉,憑油等工。 一且殘生火警時,立即予以有效的阻止,相信不一下很容易迅速蔓延r而日來火警發生的數字已比|火圈的時候,熊熊烈火,II頭担任表演的警犬, 本身而台,員工如有-

份的防火常識和經驗;術 很容易憼火燃燒,去我們一旦不小心而發生火警,勇猛的各項表演,均大爲讚嘆不矣。尤其是在跳 -的設魔方面,均有顯著的改進,但一般工廠大度 发危險浜號已與高忍,所有室內及室外的東西都在場的巴案。親眼目谜警犬的服從、迅速、

宮娛樂節目。. 于身心俱有好處,可以欣賞香港或造工業輝盘成果,並可獲得免費欣賞 毛子使用價值甚籤- 推以五毛于買入場券,而進入工线會遊街一次,對 :工展會入塲門券五角,相當于乘搭短恩小巴一次,于目前生活中,伍 一般該屬樂事,今明兩謝否資門跟時間托長中小時,即下午十時卅分停售門

·今天爲卅一工展會第一個過末,明天爲週日假期,前往工展會遊

大會十時半停售門票

週末週日與公衆假期

「案。」..

開放四天,食門張入塲觀衆,已經超過十萬名。 五天,瘓第一個週末,今日天氣朗,工展會將有一番 當刻那一屆工股合由本月十一日開放,送至許旧止且有四天,今天爲第

警攤内設臨時報案中心

外換

,很多人不 和張的所需的,本禭市一是欣賞香泡工業的新露 可時報案中心展的物品,都及家庭遊客遊工服·他們主畫

Step 內的一個臨的縮影,各商號攤位所

外客到場欣賞新工業品 ..工碌的香惱工業。」外

1則值日警員可慘矣。 意者,基會及其

少市民(本報記者)

「嘩!白老鼠也會走斑馬線!」

江

联爲

,工展會

列特展工

展大

焦不料

另一面,女良

錢大啦你對

時

少選擇看各饿片一

彩響空外狗

會場內警務攤位

幻燈片介紹警務工作

【概选民

飲料:

務市有 工民三 選 作亦天 明致十 欲試 之一

西相分

遊饕求目十之八

唔係幾仔題。」但其女 小姐一樣,香港紅十 現在遷要畀血呀。都係,捐血。如果人人好似渡

少女佔多數,不然、斜盘爾來臨而忙於佈置有「清潔香港I攤位, 居里。該等海報更呼籲 免費派發印刷精英」 大家清潔香港。

故 會場設「清潔香港|攤位

派發印刷精美海報多欺

圖中的鄭剛剛案 色鮮艷的「香港

市民可出現在直

至

骨......紅汁 取了「清香港報報,其中的歎包括 明年一月九日工期內 ,把房子個意裝飾】下一番紅星城南施,煮芳芳一;前往該攤位索取。

內至

見觀食生 可是和處悠天少唱, 然品

輸女三街

一餐店干人的見可施房播會工,籍中

命救速迅可血捐米飯 車血捐會字十紅 血捐勸場會到昨

迅工辦合聯廠中參方液集內齒展在昨車捐流字”

品藥之舉會商華戰決,並收場會工日,血動會做十

泥盒

·個賭人客樂,舞引偶然位奮一衣的們

县光

友過

康佈會之市民捐血,

位霞女與其「大空借

鷲。在宋警長迅

〖港好菌件、在上 血在紅似有、水辦踝在或內遊隨先般出燈。彩角 救那干道、粉密公、街警按人泡白手幻片:色

臺位之可重一映幻規操作

simplent definition acid is given in terms of

1974中學會考試題預習專欄 An acid is a compound which in

化學科(課程乙)(六) 王兆文

aqueous solution produces hydro- ren or hydroxonium ions as the Only electronositive-ione,e:g.

CHEMISTRY (6).

cansyere for last

(l) Iron will: roact quickly with tean at very high temperature, hydrogen and triferric tetraoxide. are:formed:

3Fe + HO

(11) Galcium will react with water in the enia, predicine hydrogen, calcium hydroxide ang areak solution of calcium

(LI) Steam will react with reg

hot charcoal, producing a mixture

of hydrogen and carbon monoxide called water gast

我

(iv) Chlorine will react with water in the cold, producing oxygen and hydrochloric acid.

hydroxon

onium ton

CH COOH

•HẸO

+CH COO

Basicity:

The basicity of an acid is the number df.hydrogen ton (H+) that can be form one molecule of the acid. For example: hydrochloric acid

monobasic monobasic

nitric acid ‘su) dhuric acid

rhosphoric acid Strong and weak acids:

'stpong acids are completely:

izes in dilute: solution.e.g

dt basic tribasic

Lon

HNO 3

Weak acids are only slightly: ionized in dilute solution and ́exist largely as molecules and their inization is reversible

¡CH GOOI

Evolve. hydrogen sulmnide from:

ome sul nhodes, e..:

Fes

HC

Bines and Alkalis

A base is an oxide or hydroxide: of a metal or ammonium, it contains oxide(02-) or hydroxyl (04) ions which reacts with acid to form a salt and water only.

Alkali is a base that is soluble in water, and forma hydrńxyi (3pns as the only: negative changed ions

"ne:and weak alkalis.

The strong alkalis are electro- valent compounds, are completely. ionized even in the solid state. and contain no molecules. e.g. calcium hydroxide, sodium hydro- xide.

Armondum hydroxide is a weak alkali, it is largely.covalent. exists: as molecules ith only a few ions, and its ionization is reversible.

Preparation:

of the metala

i. By heating or burning a meta

in air or oxygen::

2Mg +

ii. By heating the hydroxide,,car-

bonate or nitrate of a poly.. valent metal:

Cuo

Caco

2Pb(0ㄢ)

cao độ, 2P60 NO2

昨對

任已堆時察最實

嵇的有體屏蹶近

Feutralization:

Neutrialization is the combin-

ation::of the oxide or hydroxide.

tons of a base with the nydro:

gen- tons of an acid to form

water and a salt -only.

HCl + NaQit.

Salts:::

A.salt.in/a connound formed by: replacing part or all of the renlaceable atoms of hydrogen in a molecule of an acid by metallic atome or by the aniondum radicals

Normal salts: These are salts produced: when the whole of.the replaceable hydrogen of an acid

by a metal. has been re-laced

caso, etc... Acid salts:These are snlts:

reduced when only hart of the replaceable hydrogen of an acid has been renlaced by a metal,

RAESC 9nd Double salts: A double salt is. asaltiformed by the unton of two simmlersalta eis. K390A12(SO〉,24H (NH)250 AL(50)20 Amonia

→nd: NaHCO3

d:「hotassium

alum

Basic salts: A basic. salt is the:comround formed when only wart of the hydroxyl eroùne of a base is replaced by an acid groun e 6. Pb(OH)NO, and Bi(OH)NOg etc.

Prenaration:

L.Normal, salts.

By neutrilisation:

•2NaOH+H_SO>Na2SO+2H20

b. By doitble decomposition:

•b {NO3)2 + H2

+20元

ton of beat on son

Hydrates:

Cuse,

·ltanta at

Carbonates:

Carbonates of holyvalent motala. decomoses to metallic oxide and carbon dioxide liberated; e.

Caca

C.

Some dalta which do not decorina

Sidium chloride when heatodia stronely, it crackles and relts at a temperature, about 00030. Pothssium chloride hen heated atronly, it tl fuse ht

reinowaturn of about:79c.

Gotamnof Crystallization

be

fouecus solution ontain anahined water, and are caid to

hydrated. The combined water described a water of crystal [ zition)

·Deliruescante:

Dilute. hydrochloric acid is aidea to zinc. niecos in a flask to mroduce hydengers

This hydrogen is dried by passine through neveral U-tubes containing. fused calcium chibride before it deburn+"at the tin of a metal: get. The water vanour formed is condanced by the cold surface of. a: retort containing cold running water, it runs down and is collect ed in a clean dry beaker,

T7.shdy that this limddds.mnten add a drop of it to anne white anhydrous conper el hate powder, and: abserve any the white Horder turns ickly blue, showing that the lionid ferged from burnin dry hydrogen is water.

5. Acids bases and salte

A. Acids

An acid Undefined asa compound containing gydrogen, which may be partially or wholely re-laced by a metal orwith a metallic vide. hydroxide or carbonate.

M+ MrCl + "f

SOL +

NACHHC) →→→N-CL

+ H2"

CuSCy + CO. '+H_0

Acid anhydrides on water

of non-metal which d'orves in safer te farm acid such as shur trioxide.

deanamaitian, eu

BaCl

BAS, +2RC? HAS CAS

ay the formation of a volatile

NaCT

iv. Synthesis:

+

гист

Sur-thete

Terno Titus rad

Liberate carbon 4*x* de from carbointe:

+ 101 →→→ CaCl2 + H2O+CO2 5. The flute acid fth a metal

riven lydroren, e.g.:

[28) FeSOj + ila

6. Evolve sulphur dioxide fron

sulnhites, e.只+:

Hydroxides of the metals

Insoluble hydroxides--by precipitation (double decompo sition):

2NaOH+CuSO,

#230+Cn (H) 元

11. Sluble hydroxides--by the

action of water on the corros- nonding metal or its oxide! 20+ 20

Pranties:

Soany feeling.

NaOH

2. Action on the indicators:-

"14 tous. - bluc

nhenalahthalein

methyl orange

plnk yellow

3. Cannelty, to noutralyno acids. 4. With ammonium salts on heating:

WH, C1+ NOH→→→→→Kac? 20+H

5 Solution of alkalis w|17 ore-.

cipitate the insoluble hydro- xides other metals from solution of their salts, e.g.: F÷CL +38ḥON —→→Fe(OH), +3aC1

reddish-brown.

6. Strong corrosive action towards

the organic substances:

From an ins-luble base:

CuO + 950

d. Displacement:

Zn +

HASO

By oxidation;

3RD+AINO→3Pb(NO3)2+UHO

By direct combination: 2H4 + Cli

2. Acid salts:

2NaCL

In the preparation of the acid requires twice as much acid or half as much alkali as the preparation of the normal salte For examples:

H2SO

(full amount)

M-Cl + HON (hal an unt)

3. Basic Palt:

Na SC PIC1. Hormal salt

+ HCL

Acid slt

A hnnie salt may be repared hy tresting the bian thinauftic ient acid to convert the whole nf the base Int the normal sqt

2.4.

BL(OH) + ENC-40+ (

In general, above onltis NE formed by combination of the normal an ith the side or hyde xide nf the metal

Ma to form a solution.

Efforescence:

Afforasconce is the riving out of enter on exposure to air, washing and X2,00,10H20

Hygrosconic substances: Hyroscony in the taking in of water from the air, eg, “nhydr- our camber sulphate (hch turns blue).

Drvine arents:

The substances used to dry mesos Timilar solidn,n... Conclum chloride, ncentrated sulphur ç pcid phosphorus hentexido, calcun oxide and silica rel.

Questions for this week:

1. What are the chief characteristi

of (n) acids and (b) basea? State the action of dilute hydro- chloric acid and sulphuric acid on the following metals: magnesium

xinc, iron lead and copper.

2. Distinguish between: acid salt,

normal salt.

State four methods of preparing salts, illustrating each with an equation.

A enbstance has the following % composition. What is its empirical formular

Na=16.1 Ch.2 0-16.8 H20=62.9