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Crude copper can be purified by the electrolysis of CuSO4(aq) if?
Aplatinum electrodes are used
Bthe crude copper is made the anode of the cell
Cthe crude copper is made the cathode of the cell
Dcrude copper electrodes are used
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Question 32
jamb1988
Given the reactions (i) Fe(s) + X(NO3)2(aq) → Fe(NO3) + X(s) (ii) H2(g) + XO
Acopper
Bzinc
Ccalcium
Dlead
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Question 33
jamb1988
Aluminium is extracted commercially from its ore by?
Aheating aluminium oxide with coke in a furance
Bthe electrolysis of fused aluminium oxide in cryolite
Ctreating cryolite with sodium hydroxide solution under prressure
Dheating sodium aluminium silicate to a high temperature
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Question 34
jamb1988
Chlorine is produced commmercially by?
Aelectrolysis of dilute hydrochloric acid
Belectrolysis of brine
Cneutralization of hydrogen chloride
Dheating potassium trioxochlorate (V)
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Question 35
jamb1988
The thermal decomposition of copper (ll)trioxonitrate (V) yields copper (ll) oxide, oxygen and?
Anitrogen (ll) oxide
Bnitrogen (l) oxide
Cnitrogen (lV) oxide
Dnitrogen
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Question 36
jamb1988
Suitable reagents for the laboratory preparation nitrogen are?
Asodium dioxonitrate (III) and ammonium chloride
Bsodium dioxonitrate (V) and ammonium chloride
Csodium chloride and ammonium chloride
Dsodium chloride and ammonium diozonitrate (III)
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Question 37
jamb1988
When H2S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?
AH(s)S is reduced to S
BFe3+ ions are oxidized by H(s)S
CFe3+ ions are oxidized Fe3+ ions
DFe3+ ions are reduced to Fe2+ ions
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Question 38
jamb1988
Which of the following is used in fire extinguishers?
ACarbon (ll) oxide
BCarbon (lV) oxide
CSulphur (lV) oxide
DAmmonia
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Question 39
jamb1988
Which property of a reversible reaction is affected by a catalyst?
AHeat content (enthalphy)
BEnergy of activation
CFree energy change
DEquilibrium position
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Question 40
jamb1988
Which of the followingstatements is TRUE?
AThe dissolution of NaOH(s) in water is endothermic
BThe heat os solution of NaOH(s) is positive
CThe NaOH(s) gains heat from the surroundings
DThe heat of solution of NaOH(s) is negative
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Question 41
jamb1988
Which of the following will produce the greatest increase in the rate of the chemical reaction represented by the equation Na2S2O3(aq) + 2HCl(aq) → 2NaCI(aq) + H2O(I) + SO2(g) + S(g)?
AA decrease in temperature and an increase in the concentration of the reactants
BAn increase in the temperature and a decrease in the cocentration of the reactants
CAn increase in temperature and an increase in the concentration of the reactants
DA decrease in the temperature and a decrease in the concentration of the reactants
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Question 42
jamb1988
A mixture of starch solution and potassium iodide was placed in a test tube. On adding dilute tetraoxosulphate (lV) acid and then K2Cr2O7 solutions, a blue-black colour was produced. In this reaction, the?
Aiodide is oxidized
Btetraoxosulphate (Vl) acid acts as an oxidizing agent
Cstarch has been oxidized
DK2Cr2O7 is oxidized
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Question 43
jamb1988
Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution?
ACu2+ + 2e- → Cu(s)
B2Cl- -2e → Cl2
CCu(s) -2e → Cu2+(aq)
DCu2+(aq) + 2Cl-(aq) → CuCl2(aq)
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Question 44
jamb1988
Which of the following acts both s a reducing and an oxidizing agent?
AH2
BSO2
CH2S
DC
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Question 45
jamb1988
Which of the following substances is a basic salt?
ANa2CO3
BMg(OH)CI
CNaHCO3
DKSO4.AI2(SO4)3,24H2O
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Question 46
jamb1988
What volume of a 0.1 M H\(_3\)PO\(_4\) will be required to neutralize 45.0 cm\(^3\) of a 0.2 M NaOH?
A10.0 cm3
B20.0 cm3
C27.0 cm3
D30.0 cm3
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Question 47
jamb1988
Which of the following in aqueous solution is neutral to litmus?
ANH4CI
BNaCO3
CFeCl3
DNaCl
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Question 48
jamb1988
Which of the following dilute solutions has the lowest pH value?
ACalcium trioxocarbonate (IV)
BSodium trioxocarbonate (IV)
CHydrochloric acid
DEthanoic acid
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Question 49
jamb1988
A substance S is isomorphous with another substance R. When a tiny crystals of S is added into a supersaturated solution of R?
AS dissolves in the solution
Bcrystals of R are precipitated
Cthere is no observable change
DR and S react to generate heat
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Question 50
jamb1988
The ion that may be assumed to have negligible concentration in a sample of water that lathers readily with soap is?
