1965-03-12 — Page 15

真三第四第

日本四月二年已乙馨賣

WAH KIU YAT PO

日二十月三年五六九一般公年四十五萬民作中

育教借亊

華僑教育

15. 硫酸銅水溶液中通以0.6安培之電流,欲析出 鋼100克,應需時间幾何?(原子量:Gu:63-54) 解:設所求之時間馬士秒

試題預習專欄

化學科 (十四) ·王錦釗。

電量=0.6×庫侖,

CHEMISTRY

1965.中文中學會 試題預習專欄

化學科 (十四)

馮國成!

第十三次签案

乙部:

11.試述硫化氢在實驗里之裂法(附圖)及其主

要性纖

答:A製法:以通量硫化亜鉄置於錐形瓶内,装置 如圖,然後將稀鹽酸由長頸漏斗徐 徐倒下,便有硫化氫發生

FeS+2HCl→FeCl2+H2St.

B性價

1. 瑤色有腐卵恶臭有毒性

之氣体

2.易溶於水,及較空氣累重

3. 水溶液呈弱酸性反應

4.性不安定,加热則分

為硫和氢

5. 能在空氣中燃燒

6.易受氧化,呈還原性,可

還原種種氧化劑如

一稀鹽酸

硫化亜鐵

∴96500:0.6x=63:54:100

2

£=96500X100 ×___ 2

=506243(*)

63.54

故需時140小時37分2秒---()

16.某金屬0.1克洛於盐酸,在15°C,720mm.j

生氫124.3ml試求此金屬之當量

Vi = 124.3 解=720.

B=760.

Te = 273 +15

=28P

72=2731

• V2 = 124.3 ml X-720 X 273

=111.3ml..

760

設此金屬主當量為x

∴氬1克當量在NTP時之体積為234妍

.111.3:22.4X1000

2.4x1000=0.1:x

X=22.4x1000X0.11

Ammonia may be prepared in the laboratory by heating gently.

mixture of ammonium chloride and slaked lime. It is preperable

to have the slaked lime in excess to avoid having a large quantity of ammorium chloride sublime.

28/01+ Ca(OH)2]

CaCl2 calelum

2NH 1+

chloride:

EMOTILUM

chloride

a2 aked:

Bлmonia

As the gas is lighter than air (vapour density 8.5), it is collected by upward delivery. The gas cannot be dried by means of the usual drying agents, Ammonia is an alkalime gas, and consequently it cannot be dried with concentrated sulphuric acid,

H2904 concentrated sulphuric acid

ammonium sulphate

addition, ammonia reacts with fused calcium chloride to form) a complex compound with the formula, Cafly,

CaC14

Arather unusual drying agent, quicklime (which is an alkalime oxide), is used. If dry ammonia is required, the moist gas is passed up a drying tower containing lumps of quicklime, and the dry gas is collected in gas Jars by upward delivery. If the stmosphere is very humid, the gas should be collected over mercury

1/1:3.

硫化發的製備

故此金屬之當量為10:00-

-(零)

・TERESTING.

2 KMnO4 + 5 H 2 S + 3 H2SO4 →→→→→ Z Mπ SO4 + K2S04+8H20+5S↓

第十四次預習問題

單部:

1. 填-

:

1.在水溶液≠HLS能與多種金屬蓋類作用,生成不

[溶解不同顏色之硫化物沉澱,

12.下列各物傷、溶於水中呈何性反應!原因何

在?試分述之

ia, Na2 CO3, by Fells

id, No CN

ie, KNO3.

. AgNO3.

答:(a) Na2CO3 2.H.00

2.Na+C"

20H+2H>

2NaOH H2CO3

因它在水溶液中生成强酰(NaOH)及弱酸

(H2CO3),呈鹼性反應,

ibs Fe Cls

Fax +3Cl

3H2O

304+33

Fe(OH) 3HCl

HONG

周它在水溶液中生成弱酸[Fe(OH)]永强

(HCL)∴呈酸性反應。

(C) AgNO

"H2O

• Ag + Nos

·OH + H2

AGOH HNos

因它在水溶液中生成弱鹼(AgOH)及發製

(HNO3)∴呈酸性反應。

(d) No. CN

·H2 0:

Na*+ CN"

OH+

NaOH HON

因它在水溶液中生成強鹼(NaOH)及弱 酸(HCN)...呈鹼性反應。

(1)因KNO,是由強酸峡強酸所組成之盐.

故不起水解作用.里中性反應.

(区)强酸具蓝号,买弱酸头瑶掹基所生的識

都能头水

叫做

(b)中了氯的毒,可立刻以

(C)自來水加

一,可保護牙齒健康

(d) 木炭,焦碳均具性,可供冶金使用

(4)電解水時.

.在陽極上放出,

在陰極上放出,其体移比為

2. 改正下列錯誤:

(a) Na Cli

12,Zn(506)2

of Ca P.Ou

161 KS04

(e) K2 Cl

SALO FIKMxOs

• NH1(OH).

3. 用方程式表明 下列各項反應: (克)二氧化矽具鎂或炭共热.

(b)硼砂濃溶液加硫酸共热。

(6) 碳酸鈉溶液具石灰水共热,

4.爆出適合下列條件之物菌各一个

件

有昇華現象

(C) 不含氧氧化剂

山溶於水發大热

(e) 溶於水温度降低

寫出下列合物填之顏色

(4)箕水硫酸銅

(b)三仙丹

(C)硫化鋅

(d)高錳酸鉀

(4)過氧化氮

物障

6.以化學式表示下列各物漠热分解的生成物

(星須完成方程式)

(R) KCL03

(b) Pb (NO3).

(C) Ga(HCO3)2

(d) NH4 Nos

1+24+16?

14+13 +14+16 x3

One gram-molecule of NH3

The gram-molecular volume of NH3Bkh

22,4 litres at N.T.RS/

I håure of D- HNO3 - £ 22,4 litres of Nig al N, Tay

By applying the gas equation :

警警

Volume that 380 ml, of NH at 2700 and 672 om, would have at}

672 x 320 x 270 ml,

$300

294.9 ml.

0.2948 11&r9,襄

Thus volume of N- HNO3 required to react with volume of Niz

指

22.4

Hence volume of

Solution to

22.4 131,7 ml

Garbon dioxide, may be prepared in the laboratory by the action

or dilute hydrochloric acid on a carbonate of a metal whose chloride is soluble in water, e.g. calcium carbonate,

CaCO3

(b) When consentrated hydrochloric acid is heated with manganese dioxide,

it reduces the manganese dioxide to manganese chloride, the hydro- chloric acid itself being oxidised to chlorine,

Mn32 = Kn©12 ► 012 + 2420

(0) Hydrogen may be prepared in the laboratory from hydrochloric a410

by using a suitable metal to displace hydrogen from the acid, Any metal above lead in the electrochemical series may be used, #ig.

2H01 +

2n = ZnCl2

(a) When dilute hydrochloric acid is added to an aqueous solution of

an alkali, sig. caustic soda, the two substances neutralise each other to form a salt, sodium choride, and water only.

HaOH

6) When dilute hydrochloric acid is added to an aqueous solution of

sodium bicarbonate, effervescence occurs, and carbon dioxide is Liberated,TP.

HC1, +ANAHWQg

道

(r) Whan dilute hydrochloric acid added to an aqueous solution of a

Lead, silver or mereurous salt, a white precipitate will be formed.

The because the chlorides of these metals are insoluble in water, Precipitate may be sparated from the solution by filtration,

lead catate

PbCl21 42CH COOH Lead sastio scid

led Nhace

ZH(OH)2 舊為NozZnO2而溶解,但Man(OH)x 7.填-

下表

13.以最简单之方法分離下列各村混合物

(10)氧氧化鋅獎氧氧化亞錳,

碘具砂

答:(1)將此混合物置於氫氧化鈉溶液中則

1

則仍不溶解、過濾後,便可將此混合物分

(b) 將此混合物加热,碘則界析出,而砂刻

残留。

bjj

Ce(NO3)

14. 一種鹽A與苛性钠共热業生一種氣體能便 红色石蕊試紙赉藍,A溶液加硝酸銀溶液 則生白色沉澱不溶於稀硝酸,A為何物? 答:因能使濕潤之红色石蕊纸蓝之氣体,僅有 每一種氣氣,而過硝酸銀生白色沉澱者,則為

氯化物,由此可知A為氯化銨NH4Cl.

分子式 化學名稱/ 普通學稱 茄儿角水 | 硫酸鈉结晶

碳化矽

3.試描述及解釋下列化厚文化之過程,

(2)將硝酸銅放在實驗管内加热

(b)將鈣放在水中

氯水在陽光下曝晒

【HCI + AGM3g

silver

chloride AgCT + HNO3

silver nitrate chloride

Questions for next WEEKIN

nitric acid

1. (a) What uses are there of the following ammonium saites

ammonium chloride, ammonium sulphate, ammonium nitrata?

How 1m ammonium aulphate made from ammonia and calcdum sulphate? How can (1) nitrogen, (li) nitric acid befrepared from ammonia?- Give two simple tests to distinguish a solution of ammonia from one of sodium hydroxide,

2. (a) Starting with copper turnings, describe how you would prepare a

ama 13 sample (1) cupric oxide; (11) cupric chlorides (111) copper, hydroxide,

M

(b) Calculate the theoretical weight of cooper sulphate crystali.

(Cu30.5820) which could be prepared from 1 gram of copper.

9.以最简单之方法鑑別下列各組物填

小硝酸味王水

10. 完成及平衡下列各方程式门

(a) Co2+ Mg-

(b) K2Cr2O7 + H2SO4 + Hz S-

(f) HBr + Mn Oz

id 1 Aq BY + Nes S2 03.

12 / (NH4)2SO4 + NaOH.

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