貪二第四集、
日八初月二十年午丙磨艺
WAH KIU YAT- PO
勉氏蛋的廠
腰
何
硬體
育僑華
英文中學會考試題預習專欄
頁
* * * 7
第在育
廿八十月一年七六九一限公年六十五國民
跌跌持和,愛已寧息 拉躜:
三期
蟹
1
得
臨,能使品人博
SER BEL
一。省立中興大學:開三名李炳光,初技阻
、謝國華、周樹華、舉行各項學藝比
HER ·ERK BI BREWIVES
台蒻、沈雄、氫培 動向極度贏,近座統 翊關、蔥蓉英、實來該校對於學生瞑外活
明範大學王傳總壇、年來造就不少青年。但 张心等五名。省立會教敢隨見眾,十餘
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全的有國立哈娜大學 【八名。國立政治大蕃 蛊李子平、蘇護、校史悠久, 宁刻存英、方仰平, 西環之中正中分
台灣、費機中、胡省酸 中正西環分校 調爺枝、楊安琪等、空行學梅比果 泰路、張超幣、余天 屆時虢能指導。一 一、鄭雅湖、蔡昭飲、台東選肶會名流,教 吳劍、堂文華、楊育前輩,曾畢生家長
·生、蔡漢亮、何七雄該校校長就織 BR-BUG * 4. 救國總會僑生獎助, 西歴樂博士蒞臨致間
····本年度薄得蠼像得行政局非官守織的 《特腻: 位于本
55 (11) 92
生李彬川一倍。私立 随一名。台北潑,第二名林惠 台中医文化學院:葆醫,初級組第一名 大學,李明一名。 壓,第二名廣雅罗 傳第一名。私立輔仁率,高級組第一名林
東吳大學,贵实 英語朗誦比賽,
「級組1第一名林依
DC中山苑金者有:先級瓿第一名郧廨祥。
·杰英、沈著、洪恩微 第二名娜似民,第三
REKKET 40 lm +
***• (#)
明日行畢業禮」
保羅男女校
物理科
(+3)
梁海明。
PHYSICS (12) H.M.Leuno)
立中學會考試題預習專欄)
*#
JeJution.
21.(a)Conduction of heat is the process by which heat
passes from one molecule of a body to the next and the body along which it passes is known, aq a conductor. For example, when we heat a metal rod at one end, we feel hot at the other end. In the conduction of heat, a material medium is necessary but that the medium itself does not move; that the medium may be either a solia, a liquid or a gae: and that solids are batter conductors of heat than liguids and liquide are better than gases. The rate of transfer or heat is slow but that it may take place in any, direction.
化壆科
(十二)
·王錦釗
CHEMISTRY (12)
(*)
(1) Parariins
General Formule Cn Hanti
(11) Olefines
iii) Alcohols
Convection of heat is the process by which fluids become heated by the actual movement
of their molecules due to difference of density. For example, in the heating of a kettle of water, there is a circulation of the water current carrying the warm water from hottom to the top, and cold water from top to the hottom. The heat transferred by the movement of the medium in bulk and it can be transferred only in an up- ward direction. The rate of transfer is moderat - Radiation of heat is the process by which heat passes from one point to another in straight lines with great speed, without heating the medium through which it passes. For exambla the heat of the sun is transmitted through epace in this way. The transfer of heat is al- most instantaneous and can take place in all directions. Infra-red radiation warms only those bodies which have the proporties of absorbing it. (b) A Thermos' flask is a container eo designso that almost no heat could be transmitted by conduction, convection, and radiation from in- side of the flask to outside or vice versa. The figure shows the con-
struction of a "Thermos' flask. It is a double- wall vessal of very thin glass with a very high-vacuum in the in- ter-space between the walls. No heat can be transferred across the vacuum by either con- duction or convection. To reduce nadiation the inside surfaces oftthe
Glasi Silvsted
on
·Inside
glass are silvered, sa brightly polished faces are the worst radiators. Also a propar- tion of the radiation from the inside Burface will be reflected back to this surface by the outer one. The only way that heat might be loaTÀ from the flask is conduction up the solid glaas walls, and through the_cork.
()Heat is a form of energy. We understand that
energy is the capacity of doing work, and work 18 the product of force and distanos. Hence beat & form of energy if heat can be converted Into mechanical energy. This was experimented by Joule who worked out the mechanical equi valent of heat which is 4.2x10 erge per calorie.
22.(a) Water equivalent of caloriseter- 10 gm.
mass of water temperature of water
rate of energy transmitted
time of stirring
*300
• 1590 - 10/
erge/cal. 20 min.
gm.
work done by the stirrer-10x20x60 *ngs
Heat absorbed by water and calorimeter
1200x10?
4.2x10
A
-1200x10
erge
1200x10.
- cal
(*300+20)(* 15)
t 15+
1200 4.2x310
*C.
t 15 + 0.92°C.
15 020
Ingwer: The temperature of the calorimeter and:
its contente after 20 minutes is 15.92 0.
meters/sec.
speed of the bullet - 150
apecific heat of lead-0.03
mechanical equivalent of heat-4.2x10′ orgs/cal
Let me gm be the mass of the bullet,
the kingtis energy of the bullet
mv.
1.
xmx1502 100
11.25 mx 10"
if all the one
heat absorbed
-
ferge.
is converted to heat,
11.25m x10'
cal p 4.2110TM 1125m 420
cal.
by the conversion of heat energy
1125m 420
1125 -0.03x490
m. x 0.03
t
dez.c
- 89.3 deg.0 S
Answer: The temperature of the bullet will
rise 89,3 deg. in centigrade scale. Height of the piece of lead from ground
(iv) Fatty Acias,
Cn Han
Cn H2n+1.OR Cn H2n+1 COOR
Crude petroleum is a mixture of many different hydrocarbons, The first step in reiining is distil lation, which separates the different hydrocarbons? according to their volatility, that is, their boil- ing points. The crude petroleum is heated in a retort where it is converted into a mixture of liquid and vapour, which is then passed up a fract ionating column, The temperatures inside the fract ionating column range from about 450°F at the bot- tom to about 70PF at the topi
As the vapour passes up the column, Iractions of oil are collected in trays, the higher the tray the lower the boiling-point of the fraction that the tray contains.
(i) Gases and vapour or véry VOLADAL 12quids
(gasoline) pass out of the column at the tos at about 70°F.
'
The gases are used as a ruc
5.
Heat the
ני
ant
be yapour 18 condensed, purified and blended with other products of the finery to live petrol, which is used in motor cars. (11) Merdane (paraiin oil is dram of from a shelf at a temperature of about 3009. is used in heaters and lamps. Automotive gas oil and industrial Diesel ci which is used in the production of town-gas and metallurgical processes is drawn of love down in the column at a temperature between. 360°F. and 410°F.
(iv) Still further down
oil) is draw off This fraction is in ships and
(v) Part of the
distillation into gas-oil, from the fract lubricat levels nd r bottom of the
um heavy oil (fuel perature of £40°F.
buildings and boilers
ions.
`d in primary,
acuum distiliation.
sch passes outy
the top.
wn off at different
e out from the
Substitution Name
product "methyl CH CL
chloride
CRU, methylent
CH4 methân?
C12 chlorine
CHC1▸
C12
hydrogen
chloride
HC1
CHULZ +
CH C13
CL2
HC1
CH C13
Cla
HC1
+ COLL
10%
chloride
or dichloromethane
(و)
ESSURES SCHON - DEK
國升離之僑生的三型降四十四分,在夜蓄 局本年座所正餐予明(十九)日下午空- ((PE)OREAKBEX16-0 *頒發典禮經於上月卅日辆行
E-THAR BEENSAKSA
頒與同國僑生
三項獎助學金
*****NWESTBOOKOLOSI VINGRAUIUCAUSEMEGBEHÖRvah
As a catalyst T
\2_C2H210H $702
(from the air) Facetaldehyde y 2001 02.
· 2 CH2COOH +
acetic acid? (111) Sodium will react with ethyl alcohol, by disà placing hydrogen to form sodium ethoxide 2 C250 Na + Hq! sodium ethoxide #
2 CoнçÛн 2Nas
(1) Acetic acid is converted into ethy?_sustave n
esterification with ethanol.
C2HOH CH2000H CH2000.C2H5
820]
acetic acid ethyl acetáte? (11) Acetic acid can be converted into ethanol byk
reduction. Lithium aluminium hydride (Ali will reduce acetic acid in ethereal solution/ to ethenol
SH COU
+ ન
2H5OH Hao ethañol
(111) Acetic acid is first neutralised with caustic] soda to form a salt, sodium acctate, CH3COON■}
CHODOH #a04 CH3COONa+ E2O
-
The sodium acetate obtained is then heated with soda line and methane is then produceal
LaOH = CH * là phương
methane
(r) When two or more molecules of an clerine unită
together without the loss of any atoms to form KIT olefine of higher molecular weight, we say that polymerisation has taken place.
x Cn Han
→
(Cntian)x
Polymerisation is brought about simply by heating under pressure, but for ease of control catalysts are also used. For example, when ethylene is heated at temperatures up to 400°C. At pressures up to 1,200 atmospheres in the presence of some oxygen, #strong, wax-like colourless substance called polythene, (C2H4) is formed. The value of n varitm from 140 to 1,400.
(e) when water is dropped on aluminium carbide, efferves- cence occurs, and a fairly pure saaple of methane zes is evolved, w
A1493 + 12420 !=
Aluminium
carbide
5CH4 * 4A1(OH}}{ methane
1) The fractions obtained from natural pétrőlőt
contain paraffins mixed together with other hydrocarbons and ere used widely for heating, Lighting and locomoti They are also used as Lubricants and in candle-making. Methane, apart from being used so's fuel, 1a oxidised on a larra soake
carbon monoxide, which is used to MATIUI
ol and hydrogen which ta tisad in the hesis of ammonia.
point for the manufacture ethyl chloride, ethylene. dibromide, and it is polymarised to form polythene. It is a product of repening fruits, and also catalyses the ripening process, and is consequently used for this purpose. Higher oletines) are used in the manufacture of synthetic detergents, and are also important constituenta of petrol abtained by the cracking of petroleum.
(11) Ethylene ie the start
of ethyl alcoho
LIBRARIES
chloroform or trichloromethane sarbon tetra- chloride or tetram chloromethand
(1) Concentrated sulphuric acid acts upon ethyl alcoho
when heated to fom ethyl hydrogen sulphate.
H2SOL C2H5-HOOL H2O
ethyl nydrogen sulphate
ethyl alcoho
excess of alcohol is present in the mit fre ethere obtraged,
ethyl ether
If an excess of sulphuric acid is present, however, the ethyl hydrogen sulphate will break down to form ethylene.
C25.HSO CH+H250
[11) Ethyl alcohol will burn in air with a faint'
blue flame, forming carbon dioxide and water
C2H50: + 30g -2CD2+ 3 20
Under Carefully controlled conditions ethyl alcohol can be oxidised, first to acetaldehyds, and then to acetic acid by atmospheric oxygen
specific heat of lead Issumptions made:
-0.032
J. All the potential energy of the piece of lead is converted to kinetic energy when the lead piece just stikes the ground.
2. All the kinetic energy is converted into
heat energy in raising the temperature of the lead piece.
3 Neglect the part of sound energy due to
the striking, z
4 No heat energy is absorbed by the ground Therefore, we assume that all the poten- tial energy is converted into heat energ absorbed entirely by the place of lead.
Let.m gm. be the mass of the piece of lead, P.Kim ngh
m x980 z3 100 ergo
erge. -0.294m x10 quantity of heat so converted-
7
0.294m x19
4.2x10 2.94m
CAI
94m
རྣཔོ
2.94
$ - 2.2
42 x 0.032
deg.C
deg.C
Answer: The rise in the temperature of the
piece of lead is 2.2 degrees in Centigrade scale.
Questions for next week
4. Define the terms (s) squivalent weight of an 'asid)
(b) decinormal solution.
2. What is the equivalent weight of (aj sulphuric acid; (b) sodium hydroxide, (c) calcium carbonate, (d) potassium bicarbonate.
5. A solution of sodium hydroxide contains...quo, of,
NaOH per litre. 25 ml. of it neutralise 27.5 ml, oÎ ̧ a solution of sulphuric acid. Calculate
(a) the normality of the sodium hydroxide solución; (b) the concentration of the acid solution in grams
of sulphuric acid per litre.
4. Explain why we cannot make a stangara solution of
a strong acid or a strong base by direct weighing, followed by dissolving in water and then diluting. to a known volume.
5. What indicators have you used in volumetric anDJYOLO F
State the conditions under which each of thesA indicators have been used.
6. Describe how you would use a scandam
solution of .an' acid to find the weight of sodium carbonate ia á litr. of sodium carbonate solution.
>ples for revision this week!
Reptilinear propagation of light,shadows,eclipses? Reflection of light, baw of reflection, Plane and apherical mirrors,
Questione.!
23.(a) A plane mirror 4.in. tong is placed 18 in..
in front of the driver of a car. Through what width, of rear window 4ft.Gan, bebind "hin,can he see when looking into the mirror
(b) An object 4 om high is placed perpendicular to and on the axis of a concave mirror of radius/ of curvature 20 om. Find the position nature, and size of the image when the object is (1) 6 cm,(ii) 15 pm,(111) 40 om from the pole, of the mirror,
(o) Find,graphically, or by calculation, the posit/
Lon of the image of an object of height 1 im. placed at right angles to the principal axis of a convex mirror of radius of curvature 9 is, and 3 in. away from the mirror. 14.(a) Distinguish between regular and diffuse
reflexion of light. State the law of ra- flexion...
(b) Distinguish between real and virtual images,
Illustrate your answer by ray diagrams showing how a conoave mirror can form (1) a real image and (11) a virtual image.
(o) Prove that the focal length of a conmayan
arror i☐ half its radius of curvatures,
END