(b) Heat:o: neutralization. This' is the beat change when one gue equiulent of sold, is neutralized: by one gm. equivalent of a bas, the
ENCE LIBRARI
17 FEB 1975
#8 CITY HAM! 報日僑R
育教偡 頁一第張六第
日七初月正年卯乙巨变
WAH KIU YAT PO
育教僑
華
The mizzor has to be rotated through an angle, a, such that, the raya AD and A10 from window
are reflected into the eye
ein r
in 609.
1 = 359161
·AOBO
JA +
a cyolio quadrilatex
1800 #% = *83
1975
600
中學會考專欄
KIDEMIA
化學科(十四) 陳湛杰
CHEMISTRY (#14)
Solutions for Chemistry (#13) Nultiple Choice Questions
Conventional Questions
1. Le Chatelier's Principle states
when conditions under which that
a. aystem operating in equilibrium. and changed, the systen will shiri its equilibrium position in a way
will reduce the affect of the that change. In a chonice syetem, the variable conditions include. temperature, pressure and volume. (a) For the system FCP1+01 * In the vapour state, phospho- bus pentachloride diggociated to ar equilibrium mixture containing phosphorus trichloride and chlorine
he process la endothermic. The Coward
d-reaction (the reaction. towards the right side of the equation) ban the affect of loubling the volume without change
in masn. Under given experimental conditions all the three”
the three componente
behave no gxaea and conform to Avogadro's hypothesis. Applying Le onatelier's Principle would indicate that "a diminution-in- precaure must bring about a grate degree of dissociation.. Increasing the temperature of the system would
Increase, the dissociation of nhosphorin pentachloride since..thi io au endothermic process.
For
the
Oyatem
+ Hy
At experimental con
conditions, all the four components exist as gages. Since the total number of gaseous Iolecules on the left hand side equals to that on the right hard side there
zo change
is no
mylime the reactions eith
either way. in Pressure
dufore changes.
WALE
affect the equilibrium position
However, the forward reaction is ac
reaction sing carried out in very
digute aqueous solution. Thus for hydrochloric acid with sodium
liydroxia, the value is 1377Kon1
en gu aquilent.
na
HC1 (34) Nachfog)
•7001 (ay) - 10(1) + 13.7Koel.
It is found that for strong acidg
l stay bases, the values
obtained are very close to 13.7,
this is due to the fact that for
all muli neutralization reactions, basically is:
H* (áq) + OH (ay) —
H20(1).
(c) Heat of formation. This is the heat change when ous mole of a compout is formed from its element under given conditions. The formation of water from guaecuɛ hydrogen and oxygen is found to be 68.3 Konk per mole at 2500 and
atmosphere pressure.
H2 (B) + ± 02 (8) →
20(t) + 68.3 Koal
(1) Heat of atomization. This 13 the nest required to convert one ga molecule of an element from ita normal state at 25°C and 1 atmosphere pressure into free atoms (a) + 103.4Kcal = 2H
(6) deal of hydrogenation. an important information for
This is
It
astunted organic compounds, is the neat change when one mole of an unsaturated compound is cont pletely converted into the corner
ording saturated compound by reaction with gaseous hydrogen
(g) + H2(g) =
;
[[C2H2 (e) + 32.61a7
(r) Other specific hente of react- “ion include dissociation, crystal-
lization and ionization. Heat charges are 2160 usá002ated with changes that are not reptions, e.g. dilution, solution, sublimat- ion. Heat changes that involved only physical changes of state include atont heat, af. fusion and Tatent
heat of vaporization. Questions for Next Week"
The questions in this issue a re
bad to 5. Chemistry in Society; 5-1 sources of raw materials and energy 5.2.Synthetic polymers and naturally occurring macromoleculca; 5.3 Chemical" imustry.
What
at are the energy resources available to man? Indicate which. ones are most Convenient for use.
as fuels.
themic process, implying that a 2. Describe one method for the
higher temperature will favour a shift of equilibrium towards a greater concentration of carbon monoxide and water vapour. (c) For the synten Me 02210
The equation indicates that similar to (b) the number of molea of gases at the right and left-hand. veidā, rowning the same. Thus change
O pressure will have no effect
industrial preparation of chlorina What are the reactions of chlorine with
ith (a) potassium iodide solutior (b) ammonia (0) Istus solution
Water (c) hydrogen (e)sulphurt. 3. What do you wiErstand by
ollution? Indiente the chemical basis of air pollution with. referende to Hong Kong.
Klong the samo ray, OB, A
By geometry,
ZAON
= (complementary to GE) = [ION (Z1 = 20)
A ON FOR' (/1/1)
Zhou - /.OE - LAQA 2/BON! - 2/BON - LAJOR 2 (BON ·FOR) = LASDA
2/100 = 20
20420
tan. =210480
Mohayen maxímún field of view through window 2, the mirror ehould rotate 27648*: (11).
Focal length of lens, f. 20 om Object distance, u 10 am- Image distance v cm with Jens equation,
1
2010-20 cm:
A pacified, treat, sal virtual iunge in foxmish window 1, 20.oa on the left side of the leuc.. -(0)
behind
O is the image of 0.on, the
It is (15+15+10)am fro mirror.
the lens,
With D' as the object: focal length, f 20 cm object distance, u 20. Image distance v en
+
real,..
=
inverted, and diminished image is formed at a distance of 40 cm from the lens on the samĘK side as the observer.:
2(s) u: object distance
va image distance
.
u(om) 30 40 50 60 70 80 90 100 V(cm) 30 40 32 30.5 28 26.7 25 21F
upon the equilibrium.. Eowover, 25.
on
endo thermic process, the proportion
中學會考專
10
3.3 2.5 2.1.67.14 1.25 L1 1 167.25 29.3.3 36 3.7 3.8 4
the oxidation of nitrogen is, an
of nitric oxida et equilibriu
Loreases with a ride in temper- ture.
(a): For thu ayutem
- 2502 + 02
250
Here two molen of sulphur
dioxide gas mouli combing with one
volume of oxygen yielding two mo198
of sulphur trioxide gas. Therefore
there is a reduction in volume for
The
forward reaction. According to
Le Chatelier's. Principle, an ine
Crease, in pressure would
cause
shift in the equilibrium position
trioxide.
towards sulphus the process is
Tir the las T. RE
物理科(十四) 陳永熾
exothermle for the forwarû reactior 1(a)
the reveres change wou
would be
dother10.
Thus the decomposit-
ion of the sulphur trioxide would
become more and more significant Re
the temperature risés..
(e) For the system
Caco,
Ca + 002
This is an example or a haterogenous reaction involving two: solida and a gase In the case of a
closed system, ie. in the Line Foomponents are all kept in a closen
Can Brit Youls be
VeRsol, an
catablished.
solids occupy a much smaller, Volume (in relation to the mumber of molecules) when
in
with gases.
increase
fe would inhibit the forward reaction to a greatior The necomposition of arbonate. is an endothe mic
process, so that the formation or Galaium oxide and carbon dioxide would increase with increasing temperature.
Chemical processes invariably involve energy changes. The most common types of reactions that fooour included combustion, Bolution
dilution, neutralization, atumi- isstiva and hydrogenation. Any Chemical stuly of a chemical system shwuld not only include the trans- formation of reactante into pro- ducts, but should also involve a considemtion of the energy changae during the pruusss. A study of the kind
of energy ohanges involved
öflen gave some information as to the detail mechanian of the procese involved.
The simplest kind of study is concerned with the evolution cỡ
· absorption of heat and is known as thermochemistry.
However, 10
should be noted that in special:
other fome of energy changes may be important.
Thus in a battery, chemical reactions would release electrical energy; during. photosynthesis, light energy la absorbed and tinuaformed into chemical bargy; in reactions involving an increase in volunio (ong, gas evolution), mechanical work 18 done in expansion.
Reactions that give heat do the aurdunding are known se exothemic processes, those that absord heut from the Burivandings are known as tendothermic procasa. Heati
ohangoe arexpressed in teme of Foalories cr kilocalories, heat Folangas for a gwn renation fo constant under a fixed set of physical conditionst
crisphere are many types of haste of
action, the more important unene. tated below="
(s) Heat of combustion.
Thin 10 the heat changs when ore mole of a substance is completely burnt in OXYSAL. For the complete combust- lon of methane the value in 21320) per mold.
OH, (8) + 202 (x)= | 00,(6} + 210(1) + 13 Real
PHYSICS
(1) For mirror M-3
Limitation of raya re- flected into the eyes of ob perver la between C, and OA, They are the reflection of Xo, and YO, respectively.
For mirror Mat
Limitation de between OFA and "A. They are reflection of Wo* und 30" JA
Conclusion: The parson can't gon Aimselt from either of these mirrors at position A.)
(a)
Sitting at position B, observer
at position A can sec inages. from-
Mirzor Ma
1. Image position of 1:
I ie as far behind the clitor as the object is in frozE,
2. Image size:
3.
Images of plane miriors are of the same size as the object. Nuture of images, t
It is virtual, ereot, and lebelly inverted,
Mirror M
Image: I, direct reflection from
H:
1. Iie og far behi
object in in front
as the
2. same size as object is in front
3. virtual, erent, laterally
inverted,
100.69 12, Becond reflection:
Flot a graph with 1/u against 1,
and
A straight line graph is drawn. Produce the graph to cut x y-axis at A and B ruspectively. At A, == 0:
therefore
A roads 5 x
ལ
1
+
At R,
0; 100
20 am.
the fo cel Length of the cones mirror is 20 cm. 2(b)(1)
5: lateral dis
placement
20 om.
The incident rev A0 18 refracted towards the no mal DC. When it mes be the lower surface, it is again refracted. This time the emerged ray 0A is away from the
The lateral displacement is. measured by:-
Sd sin A
where X is 45° and
sin i = - oin 24°44a
380521 12
the deviation is measured =2x 0.4184 ·0,6276:
60° 12
38°521
(this problem can be solved foy. drawing in actual Boale and angle Die measured.):
(125)
A0 incidents at 90°, there is no refractionA It hits the other face.
which is
at 50
greater than the
critical ang18 D
(= sin
Total intemal reflection takes plane. The reflected may OB energ emorgaa normelly out of the prism.
(iv) as in (iii),
critical angle c
the c
(egin.
less than 45°
AO.
is totally internally. reflected twice, and emerges as 0*8 out of the Frdam.
Questions for this week
1. (a) Explain the meaning of
critical angle and total inter- bel reflections ja tahu
(b) You are provided with a cubical thin-walled, transpar ent tank; some liquid, opticai pins, and a short ruler. Describe a simple method of determining the critical angle of the liquid. Calculate
(c) How would youl
the refractive index from your meant?.
Source:
from a
(a) on the Lower face of a rectan- gular glass slab of 1.603 re- fractive index, and 2 cm thick, strikes the upper surface and the totally reflected rays out- line a circle on the lower face.. (i) What is the diameter of this.
circle? ·
(11)IF
slab of another glass refractive. Index 1.43 and 1 cm thick, is placed on the upper suface of it, what will happen?
2. (a) Make a table of three col- wans to compare the parts of a camera and an eye. In one col- umn list the various functiona to be ferformed, and in the other two identify the that perform each function
account of the com
and explain men eye defects how their effecta ted..
Give an
may be correc-
(c) An object. 4 cm high ie pla- ced 6 cm in front of a thin cor- vex fena which has a focal Leng th of 4 cm and produces a real
Find the height of the inage. image. Also find the distance the object must be moved along the axis, to give a virtual ima➡ ge of the game height.
(d) A painting consists of:-
elements
flower pot.
1daves
·colour
"yellow
flowers
green red
table cloth
peacock blue
background.
What will the painting appear if it da-illuminated by, first,
light, white
and then, by red light, and finally by green
116 what will it appear, if
observation is made under (i). a yellow filter, (ii) a blue filter, (111) a green filter.
新數學(十四)・國農
MODERN MATHEMATICS ($14)
Coordinate Geometry II.
The straight line
a. Elope-intercept forms y··¤x+b
b. Gneral form: Ax+By+ 0 0.
c. Paint-elope for: -y-
a. Two-point form: y-y1
e. Intercept form:
++
f. Nomal (polar) form:
K GOB, W:+y sin
Notice: when p=0,
the positive
direction on CN is the upward direction.
g. Normal form:
Ja Ax+ By + O
The mdioal sign is opp eita fo that of constant 0.
h. The perpendicular distance from
a line to a point..
Equation of line: Ax + By +00
or * 009 W + y sin w p≈ 0
paint: (1)
tB
real thickness -
apperent thickgra
th
Distance:
Ax¡ + By + 0
d.
EN AS
+ B
น
real thickness apparent thickness
1. is as far behind My an I iad t(1-2), ≈ 8(1 − 3) = 8 × ↓
iá front of it.:
2. same size au object
3. virtwil, erect, no later inversion with rospect to object.
(b)(1)
window !
20cm
Visw
in 450
(This problem can be solved by scale drawing and measurement.): (ii)
1.8
-Ray domes out from the prism after
being refracted twice,
Bin 1.
ain
=
009 Y, einw-p
When the given point ana the origi are on the same side, disabi Regative; when the given poirt and the origin are on the oppositive side,
dis positive..
When the given líne AB pas809 through the origin, the positive direction on the nomal ON le the upward direction.
i. System of straight lines.
System
of lines passing through the point of intersection of two given lines is given by Aqx+Bq3+0q+ K(Aq*+B¿y+Oq}
J. Condition that three linee
¡Conourrent.
If Ax+By+C, then A, B, C
A2x+B23+020
Ax+B37+0=0
= 0
日七十月二年五七九一层公年四十六国民兽中
1. Find the equation of the aira *through the print P, (-1, 3)
perpendicular to the line
5x - 2y+3)=0·
The alors of 1, is. Hence, the slope of the required line oqaule. By point-slope for.
-3x-(x +1)
or 2x + 5y -13 = 0 (Ane.) 2. Find the equations of the
bisectors of the angles formed by the lines 1 x + 376 0
L2 3x + y + 20
Let: P(xy) be any point on the bisector. Then, P is equally distant from the given lines. d distance from L to P, and d =distance from L to Pthen and are numerieally equal.. Since however, P is on the same pide of both sides as the origin,. dy and d are both negative. Hence
3+3+2
Aftar
d ruduging we got Xj+ (Ann) x + y = A For the external angle bisectorip djm
after reducing we gat
(Ans)'
0:00
of the line:
3. Find the bush P1(3.1) and the
30ing through P
Foint of intersect of L.': 31-5310 and 1x+y+1]
If
then
The system of lines is reprosented by 3x-2y-10+k(x+y+1) = 0 en
(2,1) lies on this line, X-23-1 must satisfy this equation. Hence 6-5-10+k(2+1+1)=0 whom k
Substituting this value of kaŻYT simplifying we have 21-11y4:310 Solution to exercina 13′′
1.
Ans,
ABC A(x,y; } B(xy »¥2) C& Die the mid-point of BC D= [* (= + xy ); ? (32+Y3 ·}} |
Let G be the centroid of AEC, then AG: GD = 2:1
{+2+Yzz j
2
+
2. The area of (2,3), (~3,-4)
(5.
(2,2) is
8+3+10+5
31 unit squares. Exercise 14
1. Find the equations of thờ ta
sent to the circle with the origin as centre and radius 4. which touch at the anda of the diame eter whose inclination is 150° 2. Find the gentre and the radius
of the circle inscribed in the triangle whose sides are 2x+ya12, 27-y=-4, X-23-4-0
3. Find the equation of the line
Laying through the point of
ersection of L: 2x+y+1 = 0
inte
and L1 x-2y+1 = and parallel' to
- 4x-3y-7 - 0
數學科(十四)
文長源
ADDITIONAL MATHEMATICS (#14) ·
Solution to exercise 13
1. The coefficient of x in the
expansion of (1+x)* ia
•·+(−1){} −2)••••(*_5+1)
[1(-1) (3) •*•*(-2x+3)
(2) 1
(((2) (4)16) ►*** (21)
• * • (1+x)==1+dx=jx2
Put x=0.02 then J.02
=1+0.01 (0.0004)+ + (0.000008)
1.01-0.00005 0.0000005 =1.00995 Since 225 = 152
√226 15(1 + 225)
15(1
+
-15 + 30.
450
8 (225)
8(15)(225)
-16 (225) -
15.03333 0.000037 + **
15.0333 (correct to six signifi cant figures)
2. The orthocentre i is the point
of intersection of the lines
through A,B,C perpendicular to CA AB, respectively.
Any
For
Any
given by
0.
given by
"4x+y=6+k" (11x+73+9)= 0. or (4+11kc2)x+(1+7k )y+9k!−6 = These lines are perpendicular to BC and CA respectively
= and
k- and k!= -1
The equation of AH and BH are therefore
x-4y+240 and 5x-3y-33
4y+240
Solve
1.5x-3y. 330.
x= 12 y = 9.
The co-ordi
dinates of
are (129)
orthocentre
3. tan 30 = tan 20 + tan D' tan 20 = tan 30 – tan @
gin3900se – sinecos30 tan 20 m
G083000 Be sin 20
or
sin 20 coe 29.
сов. 30 сове Hence ofther sin 29: when 20-n|
or coa 20 = COR 30 COB
a a (cos 40+ con 24)
COB 20 = 008 40
40 2n77. +
± 29
20 = 2017 or 60 = 2077 The general solution of e are.
ny,(The form
is included in the form and
x4
kx. + 1 le a factor of 22x+5x + 2
x4 - 22x2 + 5x + 2- (x2 + kx + 1)(x2 + k!x + 2)
The coefficient of x=10 ko-k*
The coefficient of x=5 2k+k 5 1.0. k5 Hence, x4
2. How many different numbers dI Ə digite may be formed with 01234567 How many of these will be event, 3. A cup is in the form of a hollow hemisphere of internal radius 400. with its top horizontal. Water le
into it at the rate of
poured
At what rate de the rising when the depth of in the cup ie Jom? :-
4. The inscribed circle of the triangle ABC touches 30,CA,AB at F,Q, respectively. Express the -RPQ in terms of the angles of the
Prove that, it denotes the area:
the area of the APQR 18
+
英文科(十四)·阮士仲
ENGLISH (#14) -
2. Composition How to tell a
By and large, # short story bas to be short (Suppose that we agree ho short da shart) and is normally written in the past- tenge. It may be written in the first person narrator or in the
third paraón Tarrator or in both.. And it contains. Zour essential Farba:
(a) Beginning (a) Climax
Developmont Ending
To begin a short story, we must introduce our characters and explain what has happened, when it has happened, and where the event has taken place. These are to be done in the first or the first two But each of the above. paragraphs. has to be developed to certain extent, paving the way for a climax, the highest point of the
the story. After the climax, atory should be finished as quick- ly as possible.
As an illustration, let us con- sider the Samson's Riddle story from the Bible:RMA
Samson, son of Hanosh, went down. to Timnath and encountered a young lion growling in the vineyardo. He fought bare handedly and tore the
Ha than went down lion in pieces. to see the Philistine woman ha
When loved and proposed to her. Samson turned aside to look at the caroase of the lion, he saw a
hones swarm of beeg in it and some hou He scraped the honey into his hands and went on, eating as he went.
When he came to his parenta
he gave them some honey and they ate it. He did not tell them from where he had
Samson obtained it. gave a wedding feast and had thirty young men as his beetmen, He asked them a riddle and if they could answer it during ·
the seven days of the feast, promised th them thirty lengths of liner and thirty ohanges of clothing.
middle went as follows;
At
The
ething
Cut of the eater came some
to eat;
Out of the strong came something
aveet.
the end of the third day they
failed to get an answer. Then they, threatened Samson's wife to get the answer for them. She was forced to
coax her husband with tears and
tander words. S seventh
day
She succeeded on the Before Samson entered the bridal chamber, the men said to him:
What is sweeter than honey?
What is stronger than a lion? To which Samson replied, "If you had not ploughed with my heifar, you would not have found out my The story above 20
dly above le analysed as
riddle,
follows:
rom. Samson, son of
(a) Beginning: From
(b)
Manoah to and proposed to her!
Development From When Sanson tumed aside to 'Out of the strong came something sweet. (c) Climax: From 'At the end of the
third day to What is stronger than a lion? 1
a) Ending! From To which Samson
replied to found out my tziddle*.
英文科 (十四)
ENGLISH (14)
Choose the baut wer
in the brackets.
Exempler 111e bread.
·Breakfast,
Write the LETTER
then rice for
(c)
the better ·B1012 C. better D. best E. the bout)
to lock after
1. Foutu brother do
hindelt.
(á old B, se old
C. mough old
3. old andìgh': 'F. `oldent)
4. He in hospital for the past two
will be B. in 0% xên. D. is being
3. The man said he was not a thief,
<A», wasn't he "B.didn't he 0. van he
D. did he B. wouldn't he)
4. One of the teachers in our
false teeth.
hool
(4. have 3. having C. 10 having
1. will be having B. has):
when the lesson wan
5. The girl fell
on.
(&. asleep 3. sleeply 0. slept.
D. sleeping E to sleeping)
Choose the answers which best completa
the following pasange.
Tony Chan likes fishing. Testerday afternoon he 5, (F. decide C. decides R. decided 3. deciding to decide) to" (try his luck at the seaside, near
his house, His brother, Sex A. wanted 7.(F. go Q to go going Sent F. gone) with, him. "8. (Would Q. Will R Rave 5 Mar T. an] I go?" he B.[ naked. "I can carry the 9.[P.
ball Q. pen R. cege S. fishing rod T. medicine) for you," Tony agreed. Soon they 'wore at the seaside. Although the fish 10. (P. that Q. whom R. what 5. who. T. where) they 10.(. caught were small they went base bappily.
42 32 2 =0 | A3 B3 03
Xo
22x2 or (x2 + 5x + 1}{x2
--5 +
→
5x
} = 0
5 ±
or
Exercise 14
AMATERA
1. Fim the equation of cirole which touches x2+у2-15x+5y=0 at (1.2) and passes through (0,2)
1. D
2.
3. B
6. R
7. Q
8. 3.
9.5
is the condition that three linės concurrent.
Examples:
5.
10. P