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An element X has two isotopes, \(^{20} _{10}X\) and \(^{22} _{10}X\),
present in the ratio 1:3. The relative atomic mass of X would be?
A20.5
B21.0
C21.5
D22.0
E22.5
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Question 1142
jamb1982
When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will?
Adecrease, since only a fraction of the water molecules has changed to vapour
Bremain constant, because the total number of water molecules has not changed
Cincrease, because the water molecules can now reach every part of the sealed tube
Ddecrease, since water boils under reduced pressure
Eincrease, because the water vapour molecules now strike the walls of the tube more frequently because of their increased velocity
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Question 1143
jamb1982
Which of the following bonds exist in crystalline ammonium chloride (NH4Cl)?
AIonic and covalent
BIonic and co-ordinate
CIonic covalent and co-ordinate
DCovalent , co-ordinate and metalllic
EIonic, covalent and metallic
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Question 1144
jamb1982
The pressure on 100 cm3 of oxygen gas at 35°C is 750mm of Hg.What would be the volume of the gas if the pressure is increased to 1000mm of Hg without changing the temperature?
A133.3 cm3
B85 cm3
C75 cm3
D65 cm3
E58.3 cm3
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Question 1145
jamb1982
0.07g of a hydride of carbon occupies 56.0cm\(^3\) at S.T.P. When vaporized and contains 14.29% by mass of hydrogen. The formula of the hydrocarbon is(C = 12, H = 1)
ACH4
BC2H2
CC2H4
DC2H6
EC3H8
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Question 1146
jamb1982
A mixture contains 20cm3 of hydrogen, 35cm3 of oxygen, 15cm3 of carbon monoxide and 10cm3 of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture?
A0.02
B0.16
C0.20
D0.25
E20
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Question 1147
jamb1982
100 cm3 of oxygen is made to react with 50 cm 3 of hydrogen, and the whole reaction mixture was then passed through anhydrous calcium chloride. What is the volume of gas left?
A5 cm3
B25 cm3
C50 cm3
D75 cm3
E100 cm3
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Question 1148
jamb1982
9.8g of solid potassium chlorate (KCIO3) were added to 40 cm3 of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore?
A24.5 mole per dm3
B0.2 mole per dm3
C10.0 mole per dm3
D20.0 mole per dm3
E2.0 mole per dm3
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Question 1149
jamb1982
When air is passed through alkaline pyrogallol and then over quicklime, the only gases left are?
Anitrogen and carbondoxide
Bthe rare gases
Cnitrogen and oxygen
Dnitrogen and the rare gases
Enitrogen, carbonioxide and the rare gases
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Question 1150
jamb1982
The nitrogen gas obtained by burning an excess of phosphorus in air has a density higher than the nitrogen from nitrogen compounds because the nitrogen from air is contaminated with?
Asome unburnt phosporus
BP2O5 vapour
Csome oxygen
Drare gases
Ecarbondioxide
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Question 1151
jamb1982
If atom X with six electrons in its outermost shell combines with atom Y with one electron in its outermost shell to form an ionic compound, then?
Asix atoms of X will combine with one of Y
Btwo atoms of X will combine with six of Y
Cone atom of X will combine with two of Y
Dtwo atoms of X will combine with one of Y
Eone atom of X will combine with six of Y
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Question 1152
jamb1982
When a little brine was added to a metal nitrate a white precipitate was formed which first turned violet and then black on exposure to ai. The metal nitrate is therefore?
Asodium nitrate
Bmercuric nitrate
Clithium nitrate
Dsilver nitrate
Epotassium nitrate
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Question 1153
jamb1982
If the temperature of a gas is increased?
Athe kinetic energy of the emolecules will decrease
Bthe pressure will decrease if the volume is constant
Cthe gas will occupy a greater volume if the pressure is constant
Dthe mass of the gas will decrease
Ethe pressure and volume will increase
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Question 1154
jamb1982
If the rate of diffusion of oxygen gas is taken as 1, what will be rated of diffusion of methane whose relative molar mass is 16?
A2.0
B1.8
C1.4
D1.0
E0.5
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Question 1155
jamb1982
Which of the following equations represents an oxidizing action of sulphur dioxide?
ASO2 + 2HNO2 → H2SO4 + 2NO2 + heat
B2SO2 + 2H2O + O2 → 2H2SO4
CSO2 + 2H2O + CI2 → H2SO4 + 2HCI
DSO2 + 2H2S → 3S + 2H2O
EK2Cr2O7 + H2SO4 + 3SO2 → K2SO4 + Cr2(SO4)3 + H2O
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Question 1156
jamb1982
Which of the following represents ethyl ethanonate?
ACH3CH2CO2CH3
B(CH3CO2)2O
CCH3CH2CO2CH2CH3
DCH3CO2CH2CH3
ECH3CH2COCH2CH3
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Question 1157
jamb1982
The production of ammonia by the haber process may be represented by the equilibrium equation N2(g) + 3H2(g) ↔ 2NH3 ∆H = -22KJ. Therefore the production of ammonia will be favoured by?
Aonly high pressure
Bonly high temperature
Ca combination of high temperature and low pressure
Da combination of low temperature and high pressure
Elow pressure
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Question 1158
jamb1982
When a solution of silver (l) nitrate is saturated with hydrogen sulphide, a black precipitate forms which is?
AH2S
BAg2S
CPbS
DHNO3
ES
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Question 1159
jamb1982
1.00 g of the oxide of metal X (atomic mass = 64) gave 0.80 g of the metal when reduced with hydrogen.
The formula of the oxide is?
AX2O
BXO
CXO2
DX2O3
EX3O4
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Question 1160
jamb1982
In the chemical reaction A + B \(\to\) C + D, more of D is formed?
Aif the concentrated of A is reduced
Bif the concentrated of B is reduced
Cif the concentrated of C is reduced
Dif the concentration of C is increased
Eif D is continuously removed from the reaction mixture
