周二第張四第
日一十月二年午丙磨复
WAH KIU YAT PO
五十五國民中
育教僑華
華僑教育
九六六年度
英中会考
試題預習專欄 ~
(Potential Energy
Kinetic Energy
.g.h.
·
mv
中題試題預習專欄
物理科
(九)
陵永熾·
Picch of scTÓW,
#
化學科
(九).
王錦釗 ®
Lengta of a lever,8 10 Lo
2 • 2zh
2gh
BA
4 ft./
KONE HNE
LA JELPS. TH
LAY
7.72
HEAT
WATER
When concentrated nitric acid is heated strongly, a colourless gar te collected in the test-tube. The gas will re-kindle a faintly Flowing splint This test tells us that the gas is oxygen. When a fest-tube" of the gas is put mouth to mouth with another test-tube containing nitric oxide, brown fumes of nitrogen dioxide are formed. This confirme that the colourless gas obtained by the thermal decom. position of concentrated nitric acid is oxygen. Equations for the reactions:"
·41 (6)
(1) HNO3 - 2420 + 4NO2 ___ O2}
CALL
2N0 +02 DILUTE NCC
2N02
M.A.
V.R.
* V.R.
0.12 x 60 7 )
17.2.7
load effort
load
7.2
250
▼
.
7.27
• £1.05
Ans. The required affort le 11.05 lb a
A of the pulley
Velocity ratio, 8.*
p
207
•
- 601
CLOUD LEIS
WH>
COLTURNI
6 Lace, efficiency.
V,
P.E. m.gh
вес.
This
By Conservation of Momentum 2.32 m.
42 = 0
M12 * #22
0.02 U2 0
0.02U1
- (0.02 • 20) v
- 2002 * 4
2002 x 4
Ana
2
• 4004 ft./
sec.
The velocity of the bullet just before] penetration" if 4004 ft./
sec.
wood-block fixed"
MS Ribówne
syst en
If the efficiency
• 100%
Pension of cord
•
133
Mass of bullet
* La
Velocity of bullet.
BAS
• 58 lb. we
Force exerted by the man
resistant force of wood
10 5¢ 10 ok
K.E
V.8 of the system = Ľ
of bullet before penetration
1 M2
❤
Caco,
When dilute hydrochloric acid is added to calcium carbonate,
A
a gas which turns lime-water milky is evolved. A gas jar of this gas is collected and a piece of burning magnesium ribbon is intro- duced inte. the gas. The magnesium. ribbon continues to burn. white solid, magnesium oxide, is formed and, in addition, black apecks are formed on the sides of the gas jar. By experiment, it can be shown that this black solids is pure carbon. The carbon could not have come from the hydrochloric acid or the magnesium ribbon. Hence this axperiment shows that calcium carbonate contains carbon. Equations for the reactions:-
91 (8)
(1) C&CO3 (11) CO2 * Ca(OH) z
(111)
CO2 + 2Mg
2H01 •
CaCl2 CO2 +
H2 O
=
CaCO3
.
2MgO + C
A small quantity of potassium chlorate is mixed with about of its weight of manganese dioxide and the mixture is heated unt il
_constant weight is reached. The residue is allowed to cool and is heated gently with some concentrated sulphuric acid in a hard glass Lest-tube fitted with a delivery tube A green gas is evolved, which will turn starch iodide caper blue, The gas given off: is chlorine. This shows the presence of chlorine in potassium chlorate. #quations for the reactionst-
Qt (d)
~(1) 2KC103
P
28C1
(11) 2KC1 * MnO2 2H2. SO, * (111)
3:02
* 2KI* - 2KCI 像 12
cesag
An aqueous solution of copper nitrate is put into cube. A small quantity of fresh gine filings are put into the solution, and the mixture is well anakan. A reddish-coloured solid is obtained. This solid is copper as it will dissolve in nitric acid with the evolution. of brown fumes, and forming a blue solution of copper nitrate, This experiment shows the presence of mapper in copper oltrate. Equations for the reactiones- "
~ (e)
(1) 20 (112 *Cu
-
Cu (NO) BHNO
•
201803/2 • Cu
*
• Cu(NO3)2+2NO 74H2O
Some dry ammonis gas is passed over heated oxide. solourless gas is obtained.' 'On testing for the gas, it is found to respond negativaly to the teita, applied for all the other common gases. This gan là sátrogen wilch is rather inert gas..
Mit Gha
+
If distance moved by load. 1.
of forw
# the Principle of wome
work outpout ↑ work
Resuming chat the machine is frictionless, the wom work used in raising the govable pulley block.
(1) If the Load to 30 lb.
effort
30
*ffort
More Laput
Work output
LO
• 10 lb...
30 ft-lb.
WORK OUL Out
#gele triput
LOOS
75%
If the Load is 90 ib.wt.
affort a
• 90 ›
effori.
= 25 10 m
Work tepun
•
25.
▸
100 f.10.)
work out pour
·
90 $.10.
Ej rij concy.
*
work, outpUL work input
90
100
901
1009
WATER
Equation for the reactions"
0.2
*
2NH3 • Cu o
►
The precipitate obtained is silver culoride. "AgC)
AgCl - 108 55.5
- 243.5 weight of ag in 145.5 gms of AgC)
• 108 gm
0.717 P
* 108
L4 3.3 * 0.5
ין
0.212
g.
Weight or stiver sing”,
-5.of silver. LO CAB_BLJOY
2001
To t
COLVANGESI
ANITRECENS
18
K.E. of bullet is used to penetrate the wooden block, that is
(** } ft.)
* *
£ £ _- 142 pul.
Wooden Block movable.
mase of wooden block
#locity of it after impaét
„Panetos tion of bullet
Conɛstrasion of Momentus,
• ft.
Latly
£20
re/
100
wooden block la movable, K. B. of bullet
** work done in genetration • K.Š. of
2
*
Z
(4)
Så Lo
combination,
Fetencies for loags of 30 10 are 75% and ROT respective 17.
Work dong by the engine in 1 sec
- work done in raising water
work done in jetting put water
x
x 32 ft-pdl.
60
2
10" x 17
I
10%
-{
+
*
-) ft-lb.)
60
60 x 32
103
•
(1716) ft-lb.
Work input on the engine in 1 sec work output
efficiency
* 33 x
ft-lb
x 33 x 3 rt-lb 1 22 x 103
Ans The chat penetrates 54 inž
Questions (10)1
Ansa). A lump of metal weighing 120 gm. is a mixture of copper
(a.p. heat 0.10) and iron (a.p. heat 0.12) the metal
is immersed in boiling water and then put into a calorimeter of water equivalent 5 ga. containing 65 gm. of water at 17.03
If the temperature of the mixture is 30°C, find the weight of iron in the lump.
(b) 7. gm of ice at -16°C are dropped into 38 gm. of water at
24 contained in an aluminium calorimeter weighing 50 go..
Taking the and the temperature of the mixture is 10°C. specific heat of aluminium as 0.22 and the latent heat of fusion of ice as 80 cal. per gm., calculate the specific heat of ice.
((o) A piece of wet içe weighing 15 gm. was placed in a
calorimeter of water equivalent 12 gm. containing 120 gm.) of water at 26°C. If the temperature 0 of the mixture was 16 C, what percentage of the wet ice was water?
latent heat of ice" 80 dal" per ga.) by ay sa a
6) (a) & is a sodium sar since only so01 sajus will give o
yellow coloration to the non-luminus Bunsen flame.
X must be sodium bicarbonate. Socium carbonate does bus decompose on neating, out sodium, DiCarsonALE Wil) decompose on nealing witf, une evolusion of when wall turn lime-water milky
ZNA HCO
carbon. Qioxidi
Na2CO • A2 = CO2 4
CO2 + Ca(OH)2 Call ng ở
(b) The resique I is sodium carbonáte. Dilute ac105 reach WILD
carbonates evolving carbon dioxide,
Nag CO2
• ZHCJ
*-2* C* My ~ CO2
Questions for next week-
use for each of the following:
Power of the engine
22% 103
3 x 550
ft-lb
sec.
n.p. Į
C
200
•
,h.p. }
ນ.
3.
P
13h.p..
Ans. The horsepower of the engine is 133.
Mass of wood, M2 20 lb.
State one
ammonia, ammonij. sulphate, ammonian chloride, ammonium nitrate, ammonium carbonate
Write une cames and formulae of four subsuances which wif)
Give equations for une liberate chlorine from hydrochloric acio.
reactions.
The solubility or paza32um nitrate Is 75 at 45°C. ano so at −20°C+TM-Potassiumnitrate_is_addeg_lo 25 em. of water at 45°C. until no more will dissolve. What weight of potassisie #111′′Come out of solution on cooling at 20°C.
Sulphur dioxide-is-usually considered to have reducing properties How do you account for unist. Give an example where Bulohu 01oxide may De considered to act as an oxidising agen
It you were given two white ac1105
Der Cold that one
descride now voù voulo
· Has a chloride..and the other & skipnale
"Tina out" Conclusively which was wh10 vele person wing na de munte cu dia
Sulphuric acid has three main propesLea reaction illustrating each and describe how you could demona·· urate it in the laboratory.
15.
initial-vel-of-woody Initial vel of bullet Final vel. of combination
By Conservation of Energy,
2. A ga. brass weight at 14 C is dropped into liquid nitrogen at'
its boiling point (-1969.) The gaseous nitrogen evolved has a volume of 140 c.c. at N.T.P. Rf the density of nitrogen gaa at N.T.P. is 0.0013 gm. per c.c. What is the latent heat of vaporization of liquid nitrogen? (Specific heat of brass 0.091)
Holten lead at 500°C is poured into $5 ga. of water at 14°C)
·contained-in-a-calorimeter of water equivalent 5.gm...and.the. temperature of the mixture is 90° the weight of lead is 240.g., ita latent heat is 5 cal.per gm. and its specific heat molten is 0.04.. solid la 0.03. What is the' melting) point of lead?
Mass of bullet, M,
0.02 lb.
A vessel of water equivalent 10 gm. contains 100 gm of water andcols over a certain range of temperature IA TO ZEN. THE water is replaced by an equal volume of paraffin and the vessel} -now-cools-over-the-sama ranga in temperature in 6 mio. If the density of paraffin is 0.8 m. per co.. what is its specific heat?q işinə diplomu ala
what
piece of iron of uniform cross-section floats in mersury wzon 25.06 cm. Lesersed". If the temperature rises by 100 will be the length immersed now?