JAMB UTME - Chemistry - 2008
Ibeere 1 Ìròyìn
The experiment that showed that atoms have tiny positively charged nucleus was first carried out by
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Ibeere 2 Ìròyìn
In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to
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Ibeere 3 Ìròyìn
Diffusion is slowest in solid particles than in particles of liquid and gases because
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Ibeere 4 Ìròyìn
In the periodic table, the electrical and thermal conductivities are properties of elements that
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Ibeere 5 Ìròyìn
Which of the following compounds of trioxonitrate (V) will decomposes to give dinitrogen (i) oxide and water when heated?
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Ibeere 6 Ìròyìn
In the course of purifying water for town supply the water is passed through large settlings tanks, containing sodium aluminate (III) to remove
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Ibeere 8 Ìròyìn
The oxidation state of carbon in HCOOH is
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HCOOH
O.N of H + O.N of C + 2* O.N of oxygen of
H = 0
1 + X + 2X - 2 + 1 = 0
2 + X -4 = 0
X = 4 - 2 = +2
Ibeere 9 Ìròyìn
Use the diagram to answer this question.
The colour of the fountain water is
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Ibeere 10 Ìròyìn
A hydrocarbon X with a molar mass of 26 consists of 92.3% carbon. What is its molecular formular
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% of H2 = 100 - 92.3 = 7.7%
mole = 92.3/12 7.7/1
7.1/7.1 7.1/7.1
empirical formula = CH
(CH)n = 26
(12 + 1)n = 26
(13)n = 26
n = 26/13 = 2
molecular formula = C2H2
Ibeere 12 Ìròyìn
117.0g of sodium chloride was dissolved in the solubility in 1.0dm3 of distilled water at 25oC. Determine the solubility in mol dm-3 of sodium chloride at that temperature
[Na = 23, Cl = 35.5]
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Relative molecular mass of NaCl = 23 + 35.5 = 55.5 g/mol
No. of mole of NaCl = 117/55.5 = 2.1 mol
Ibeere 13 Ìròyìn
Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of
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Ibeere 14 Ìròyìn
If the silver mirror test is positive, it indicates the presence of an
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Ibeere 15 Ìròyìn
If a given quantity of electricity liberates 0.65g of Zn2+, what amount of Hg2+ would be liberated by the same quantity of current?
[Zn = 65, Hg = 201]
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Ibeere 17 Ìròyìn
16.8 g of sodium hydrogen trioxocarbonate (IV) is completely decomposed by heat. Calculate the volume of carbon(IV) oxide given off s.t.p
[Na 23, C = 12, O = 16, H = 1, Molar volume of a gas at s.t.p = 22.4 dm3]
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2NaHCO3(s) → Na2CO3(s) + H2O(l) + CO2
Relative molecular mass of NaHCO3 = 23 +1 + 12 + 16 * 3 = 84smol-1
2 * 84g of NaHCO3 will be liberated 22.4dm3 or CO2 at s.t.p
16.8g of NaHCO3 will libertae (16.8 * 22.4)/(2 * 84) = 2.24 dm3
Ibeere 18 Ìròyìn
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Ibeere 19 Ìròyìn
If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to
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Ibeere 20 Ìròyìn
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Ibeere 23 Ìròyìn
300 cm3 of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume
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P1V1= P2V2
800 * 300 = 650 * V2
V2 = (800 * 300)/650 = 369.23 cm3
Ibeere 24 Ìròyìn
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The correct answer is 11.
pH = -log(H+) Or 14 - pOH
pOH = -log(0.001)
pOH = 3
pH = 14 - 3 = 11
Ibeere 25 Ìròyìn
The rate of a reaction usually decrease in the concentration of reactants because
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Ibeere 28 Ìròyìn
The atom of an element X is represented as yzX . The basic chemical properties of X depend on the value of
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Ibeere 31 Ìròyìn
In recharging a lead-acid accumulator, the reaction at the cathode can be represented as
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Ibeere 32 Ìròyìn
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
From the equation above, calculate the mass of sodium hydroxide produced by 2.3g of sodium.
[H = 1, O = 16, Na = 23]
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2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
Relative molecular mass of NaOH = 23 + 16 + 1 = 40smol-1
2 * 23g of sodium react with water to produce
2 * 40g of NaOH
∴ 2.3g of sodium will react with water to produce
(2.3 * 40 * 2)/(23 * 2) = 4.00g
Ibeere 33 Ìròyìn
NH3(g) + HCl(s) → NH4Cl(s)
The entropy change in the system above is
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Ibeere 35 Ìròyìn
The product obtained when a mixture of benzene vapour and hydrogen are passed over nickel catalyst at 180oC is
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Ibeere 36 Ìròyìn
The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is
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Ibeere 38 Ìròyìn
When a few drops of water is added to a blue anhydrous cobalt (II) chloride, the colour changes to
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Ibeere 39 Ìròyìn
The uncovered raw food that is sold along major roads is likely to contain some amounts of
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Ibeere 41 Ìròyìn
Insoluble salts can be prepared by
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Two soluble metal salts react with each other to form one soluble salt and one insoluble salt . Lead nitrate solution and sodium chloride solution react to produce solid lead chloride , leaving soluble sodium nitrate in solution. The lead chloride can be recovered by filtration.
Ibeere 44 Ìròyìn
Use the diagram to answer this question.
The gas that can be used to demonstrate the experiment is
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Ibeere 47 Ìròyìn
Reduction of nitroalkanes, nitrites and amides is a route for the preparation of
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Ibeere 48 Ìròyìn
0.05 mol dm-3 HCl is neutralized by 25 cm3 NaOH. If the volume of acid used is 32.00cm3, what is the concentration of the base
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HCl + NaOH → NaCl + H2O
CAVA = NA/NB = (0.05 * 32)/(CB * 25)
∴ CB = (0.05 * 32)/25 = 0.064 mol dm-3
Ibeere 49 Ìròyìn
When a solution of ammonium trioxocarbonate (IV) is added to a solution of an unknown salt, a white precipitate which is soluble in dilute hydrochloric acid but insoluble in ethanoic acid is formed. This indicates the presence of
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