可一味(〇九九一年九十七國民華中:
全國政協經濟委員會調查組建議
觀濟委員
:附發虹水河水缸資積,而好醢族鉅資源的綜合開發利用 展橫向聯合和商品經濟開雕有效通道, 立,以聲要點、桂南省與經濟發襄山楼,山啟東及港澳地: 台灣查組過約、打水阿水力資数的開發,經過多年的 西江水系的水力资源後,向中央運儀「八立」期間加速之稱。它的梯版批發、梁化通航、將塔斯比粵省區發一 何組成的潮查組,近制处、市翁案調穎水河—上費用、廣西到廣東的唯一水土交通錢,有華兩舊帝水道 全國政經濟委員會林作、羅西北、陈洪侃三位姿 、粵三省經濟發展的長期需要,紅水河——西江水系是 期以来受底力不足的沙挺、魯布格三黹站已建成併發谁i岩灣、天生橋二 前期工作,已典了大規模開發的條件。日前,大化。
·對自然資姝難以睚發,甚至一些在建的大型埴月也受:資萆已具備了豐富的經驗,掛,約兩省對開發打水河也
西山頂於敬,法,好嘅埃进,毅電站正在如果聽設中。水電工作者對開發紅水河水力,
加速開發紅水河水資源 帶動黔桂兩省經濟發展
;正传
作查聯
·佛在南
·
ernational: Diveet Dia.
V. Choice of Means of Communications.
To be efficient and effective, any communications methods
fulfil the following conditions: a. They should be economice) and
accurate.
They should be as-rapid, required,
The essential considerations should. include:
a. Cost/speed.
The more faster transmission results in higher costas
However,
it is justifiable to pay higher cost in return for immedate communications.
Secrecy Where
confidentiality
necessary, the message could be sent by a courier service.
G. Security
Registered letters may be used
if the message is ensured to. reach the recipient,
d. Record of proof:
If written confirmation of thẻ"
communication is essential, registered walls or telex would be used.
e. Accuracy of transmission
"If the message should be sent, as accurate as possible, telephone communication
misinterpreted.
f. Convenience
The sending and receiving of the message should be convenient .both to the receiver and the
sender.
育教日十三月九年午庚醫夏
199】中學會考預習專欄
明德出版社
MILL & DALE PRESS
Accounting (71
Year End Adjustment
„K. Definition:-
Kwok
Depreciation (1)
Depreciation may be described as the portion of the cost of fixed. assets that is deducted from revenus. for asset services used in thre operations of a business. It is
closely linked to the concept of business income. Since part of thes
service potential of depreciable
assets is exhausted in the facome- generating process each period, the
cost of these services must reducted from income
bé...
depreciation) in measuring periodic
prófik dat losauru
Causes of Depreciation:-
sear and sears: -
Depreciation may result from physical "uglerioration" due to operating: use. these physical forces termate the usefulness of:
1991. 中學會考積習專欄,
出
AFE & DALE PRESS
Chemistry (7)
Reviston Notes Reactions
Redox
Electronic Theory of oxidation Reduction Reactions.
14: Oxidation is the loss or removal
ore br more electrons from. chemical specres such as an atom a molecule, an inn or a radicalis
adical
rogu
1,2 Reduction is the aligsor plance
of one or more chemical species."
e.g. Sa
oxication
oxidation
.3 An oxidanti
which accepts of during a reaction, electron acceptor;
· species. electrons 1ts an
1.4 A reductant is a Chanical species which donates or loses Fectrons during a reaction,
UAis an electran donar v
1.5 Sicce oxidation and reductaer reactions always decur, Logewer, so they are more commonly known as the redox reactions. Hence, a re reaction is, according to Electronic Theory, one whi involves a transfer of electrons. from a reductant to an oxidant.
0.9.
之效,造成爲戰
·解报的學說,反增出聽醒 晚期。中央来體制已發底至成熟 階段,法家之所,成為這按 「政治理發展。
(a)
豪、知識份子的 原上籍,亦已佈 治色彩(事實 躞,既可欣為體,
·茲將別比較儒,法學說異同
*自然演變成隘比較內容儒家
TOERNA BADI
HALL ASTART.
抬入口
假此宜。」的政学記內容,强调出、
家思想的代表性
TORM DEXT- DEA-H
Y
BOETZERN
ONATE 2*32*
5+
E郪割傳訛的法家
DEKRADENJE GA
经漆轢源,人料器 去管治。他推磬
PERMES 263 BEN JR MOON 嗨,但其中無一件 買取を子 KRTEXE
EMA 16
STAABAR
功必識,有雅必
日文一解群求用
ORTAJ
F瓘行。
必F
*林上旧勢,移轴
【唯光高位更能治天
W
A MENUS
UB FATA.
EFES
JELENAAT.
所以第一
一、懷的耳朵去
4
作戰試行必求其功
(61)AKOSE
软化承建繫社會秩,
BEN DUILUTTAJE 行學說,鄭衍烤淡天權」, JERABANG BANGIZ PARADE
合起來,射進出至魂終始(如果 灣東大維,大年紀金)的讚 華及帶定倫學務。
爲代表,主城辨別名實同異,晚 檸斯為之術。
字述腹家;以并行為代表,主
辆國台與人民同耕业業。
代表憑三寸不湖之苦,谁特君
DUKTYNY
OFK BENTEK =
TETNIHOK-KZAV
BAEZAWM, TOURIN
或簽國政治思想的笨導主流,
BUNKEREMMUZ
DEZES
之本。「踏老之學」作
出來。
MSTER BRA · **@@ 德獎,街遇,而成一家之言
(廣分:
E
(告類)
18
oxidation(lass.of.e
(aq)+1"(aq)-Fe="(aq)^ zl2(aq)
Seductionfgain of e)
electron is transferred from an
on to fe for
oxidation!loss of
Zn{s}+Cu^^(aq) -+2n^* (aq)+Cu(s);
ceduction/gain of e).
(Two electrons are transferred
* 20-atom to a Cu2 lon:))
Question 4.1
State the oxidants and reductants
the following redox reactions.
(a) ZFe(s)+3C), (g) -- 2FeCl3(s)
[Pb) Mg(s)+20*(aq)
(c) 2Fe *(aq)+Sn2 (aq
(d) Cuts)+2Ag(39)
2. Oxidation Numbers
2.1 Oxidation numbers are directed
numbers assigned to the elements,
whether free or combined, according
to some simple rules. The sign of
af oxidation number must always
cone before the number. There is
no physical significance to he
attached to these arbitrary numbers it any circumstances.
2.2 Rules for assigning the Oxidation
Numbers (0.N.);
(1) Atoms in the elementary · (free) state are given an 9.Nt of zero,
(2) The Q.M. of a munatonlt ion is simply the charge on it, Aisition
(has a positive Q.N.Zuhiisan anton has a negativo upo, e,g. Upe 0.N.*S
of Na+, Fe and (c) are +1
and respectively..
(3) In a polyatomic structure the
fixed items by rendering then incapable of perforining the services for which they were Intended and thus set the maximum limit on the economic, life,
(2) Obsolescence::
assets!
It refers to the "effect of innovations and technical. improvements on the economic Life of existing assets. (3) Inadequacy
Depreciation
maybe.
recognized as the effect growth and changes in the scale :-of
firm's operation terminating the economic life of Assets.
في
(4) Passage of time:
報日僑華
line method of depreciation is. that each year of service absorbs on equal portion of acquisition cost. Depreciation. per year is thus computed as follows:-
Depreciation per year
*Acquisition cost - Estimated disposal value Estimated year of use
五期星་日六十月一十(〇九九一)年九十七國民中( 24 )
(2) Reducing Balance Methodi
sometimes This method, called diminishing balance. method or fixed-percentage-of- declining-balance method, is used to reflect the fact that some fixed assets yield either a greater quantity of service or more valuable services in early year of use. Under this method, a fixed percent is written off from the reducing balance of the
a's set account (1.e. the net book asto value) each year, sa
the asset to the redute estimated disposal value at the And of its life.
Example:-
Acquisition cost of
the machine pok
$10,000
Estimated disposal value
$2,000
Estimated year of use.
·years
The
Depreciation per year
pre-centage (depreciation rate is
As time goes by, the assets' value may decrease and depreciation reflects such fact.
$10,000 -- $2,002-
$1,600.00
Estimated disposal valde
cquisition cost
years of use).
It refers to the reduction
In
examination,
the
depreciation
rato
frequently supplied.
(5) Depletiontest
an market value of using the fixed assets..
C. Factors Affecting
Calculation:
(1) Estimated year of use.
This amount of depreciation will be treated as expenses in the Profi ind Loss Account.)
Depreciation
Year Dennulation)
Accumulated Depreciation
Het Book Value of the machine
$1,600
Example:-
.3.200
4,800
: 6,400 9,000
| (2) Cost of fixed assets
dispusa value..
131 Method, of calculation.
D. Simple Methods of
Depriciation:
1 st
12 nd
1.600.
3rd
1,600
14, th
[5-th
Calculating
11 Straight-line:-
The
distinguishing characteristic of the straight-
more électronegative atomis giver negative 0.1 and the less electronegative atom positive O.N., e.g. In the compound C, the ON OF CT is and that of as chlorine i5 v more +1 because electronegative than incinerate (4) Hydrogen is usually gaven eri 0N, of f+1 in all its compounds except the metallic hydrides, in which it's 0-8 -1.
(5) Fluorine, Being the inust electronegat, efemot always given an 0.NFL.C (6) Oxygen, in second most electronegative termer (next to. fluecipe) usual has an O.N. of 22
T. (ts: compounds except the Leroxides, where its ON of -1, and fluorine oxide #Fe,0) where
(7) The algebraic sum of the 0.My or all the atoms is zero for a neutral compound. but equal to its electronic charge for a polyatomic
(8) The 0.N. of any atom in a chemical species composing of two or more elements may be obtained by finst assigning a reasonable O.N. to each ur the other elements in. the species.
2.3 It is to be noted that the same
element might nave different. oxidation numbers when contained in different chemicals species, e.g, Carbon "bas an DN. of 42 in CO but +4-10 CO
Question 4:2
Assigh 40 CR to bach of the underlined elements in the following chemical species, (af: Cafe (d) N80
(b) Mys () Mn
d Change in Oxidation Numbers and
dation-Reduction Reactions
Anton is said to be oxidized if pai tiga rumber is increased of becomes meas positive during, a reaction
atum sy
reductant..
5,600 1.600
[10,000-160048,400 10.000-3,200-5,800 16,090-4_800-5,2001 10.000-6,400 3,600. 10,000 8,000-3,000*
If estimule 1: "accurat the net book value of the machine would ecua Lo estimated disposal value after the machine had been, tull depreciated.
readfly a chemical species donates electraris, the stronger a reductant it will be. Similarly the more readily a chemical species accepts electrons, the stronger an oxidant. Since it will be However, donating electrons and accepting e ectrons are opposite processes. se a stronger exidant must be a weter reductant and vice versa
some chemical' in
in one
in anothe
with at substan
a reductant.)"
roxidant,
This implies that the oxidants and reductants are actually celative. terms and their applications depend on the relative strengths of the
Acquisition cost. Disposal value
Estimated year of use
Depreciation rate
$2.000 $250
3 years
substances concerned as cxidant or reductant. In the easible above. it 15 obvious that sulphur dioxide. has a reductio power stronger than xygen but weaker than hydrogen, sulphide, so, it reduces uxygen hut is reduced hy hydrogen sulphide. However, powerful-oxidants. reductants always act as such. On y theweaker oxidants and Feductants can act as both oxicants and reductants, according to the *substances with which they feact-s
and-
4.3 In general, the metallic elements.
dey usually the reductants because ajopa leztrons, readily to furn lokale the non-metallic taraftan oxidants as they electrons raadily to form The more electropositive metal, the stronger will be its reducing power and the more electronegativa x
etal, the stronger
idizing.
power
5. Table of Some Common Oxidants and Reluctants
Oxidants.
Acidified potassium. permanganate [KM00,}
Alkaline potassium.
permanganate
Acidified potassium::: Michremate
Halogens (e.g. 2).
Hot cond. sulphuric
acid-
Hot comic nitric
Acidified hydrogen
peroxide
wil nitric acid
Reductants.
Usual Changes In Terms of Electron Transfer
CUBLIC
3.2 An atoms is said to be reduced
its oxidation number is decreased
or becomes more negative during a reaction. The atom is thus oxidant,
increase in .N.
(oxication)
decrease in CÂNT
(reduction)
3.3-A redox reaction is one during which there's a change to the oxication (number of one or more atoms
8.9.
cecrease in:0;
(reduction) +1-2
+2+1.
increase in 0.N.}
Toxidation)
Hence, "H" is oxidized while Kratom inwater reduced in the above reaction,
Question 4,3
State whether the elements under ined mare -oxidized, reduced or neither
the following reactions,
(a) 2Ag+£12 = 2AgC1
[b) 4MHz+502 -- 4NQ+6H2O
[x} SQ2+DH ̃ → H$D
(d) ZH)+2NDḤ
[e} [0, +5! +6H*
4. Relative Strengths of Oxidants and
Reductants
1 According to the Electronic Theory of redox reactions, a reductant is
an electron, donby and an oxidant is aa. electra (decpobory
The mare:
-Hydrogen sulphide,
Moist sulphur dioxide (0) or sulphytes.
(507
Neutral or alkaline. hydrogen peroxide- Most metals Latone. or in dilute acids, eg. Na, Mg, etc)
Carbon with heated metal oxide
Carbon nunoxide (CO) with heated metal axide Iodide ion (I") in dilute acid.
tront11) on in acid medium
Tan{11} ion in acid
medium
Balancing
6, Balancing Simple Redox Reactions
radox. reactions is complicated, rather
However simple redox, "reactions can be balanced quite readily by using the fact that the total number of electrons transferred in each of "the half-reaction equations of a redox reaction, live, the oxidation reaction and the reduction reaction) must be the same.
e..
(1) Balance :
Fels)+Cu(aq) fe2+(aq) +Cufs)
Step 1:
Write down
the two half- reaction: equations.
MIRARIES
Terms Of Electron Transfer
Stop Z
Stoce the number of electrons is the same to the equations (1) and (2), so, simply adding up the two to eliminate the electrons, we at once have the equation halanced,
Fe Cu
(13) Balance
Step 1
write yow the reaction equations.
AF
5 +26
Step 2
In order to make the number of electrons the sage in the equations (3) and (4), we have
50%
Depreciation Net, Book Value x
Year end
Depreciation
Accumulated Depreciation
Het Book Value
st 1,000
500
1.000 500 750
$.... ,000-1,000 1,000 *500*500 (000-1:750 250
做
It equals to the estimated disposal value,
(3) Revaluation:-
The amount of depreciation of the year may be calculated simply by revaluating the value. of the fixed assets at the end of the year (and, comparing them with that at the beginning of the year adjusted with any new acquisition,
Example:-
Value of machine
at last year end
Value of machines
at this year end
The depreciation of this year $3,400
$5,000 $1,600
END
to multiply equation: (3) and equation (4) by 3
[3] × 2,241 + 241- (4) x 3:35 Step 3
$5,000
$3,400.
15) 635n,,, (G).
"Adding up the equations (5) and (6) to eliminate the electrons, we have the following balanced equation.
2A135h
Question 4.4
Balance the following redox reaction e2* {aq)+C},{aq) → Fe3*(aq}+C1 ̈(aq)",
Solution to Q.4.1
(a) Fe, is the reductant as it has
electrons.
CT 15 the Coxidant accepted electrons!
(b) Mq is the redactant.
oxidant.
(c) Fe*(ag) is the oxidant.
is the reductant.
4d) Qu(s) is the reductant.
the oxydant..
Salution to 0.4:2.
(a), 0.N., of H
0. of Ca
ON bf Ca 12
(b) 0.8. of 0.
0 N of AT
SOME OF 41
16) 0.8. of
ON OF I
(d) 0. of No
as it is a meta")
ydride)
ON of O + (−) ̈× 2, #
ON of 0 =
de) 0.M. cf 0
20.N. of Mn
·D.N.
N. of Cb,
Solution to 0.4.3
1 is reduced as
decreased from 0 to
Nis soxidized as its increased from 43 te +2,
_{c} ${0}2+[OH]* → {H_s. (O)g]"
the
Sis neither oxidized nor reduced, This is not a redox reaction as one of the atoms has its C.N: changed.
+2 -2 +1 +1-2+1
(d) ZntOH)2+2{a}{0H) → (Na)2Zn(OH);
Zn is neither reduced hor oxidized. This is not à redox reaction as none of the atoms has its .N. changed.
(0) TQg +51 +6)|* ~
11 10. is reduced as its h has decreased from 15 to 9.
Solution to 9,4,4
Fox (qq) → Fo3*(aq) + e Cl2(aq) + 20° 2015(ag)
{2}x): «Eg2+(aq) → 2Fe** (aq) +2
(3)+(4): 2Fe
2Fe2* (aq)+C] ¿{99)
(2)
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