JAMB UTME - Chemistry - 2008
Pergunta 1 Relatório
In the periodic table, the electrical and thermal conductivities are properties of elements that
Detalhes da Resposta
Pergunta 4 Relatório
Detalhes da Resposta
Pergunta 5 Relatório
300 cm3 of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume
Detalhes da Resposta
P1V1= P2V2
800 * 300 = 650 * V2
V2 = (800 * 300)/650 = 369.23 cm3
Pergunta 6 Relatório
The rate of a reaction usually decrease in the concentration of reactants because
Detalhes da Resposta
Pergunta 7 Relatório
Use the diagram to answer this question.
The colour of the fountain water is
Detalhes da Resposta
Pergunta 8 Relatório
If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to
Detalhes da Resposta
Pergunta 9 Relatório
When a few drops of water is added to a blue anhydrous cobalt (II) chloride, the colour changes to
Detalhes da Resposta
Pergunta 11 Relatório
The oxidation state of carbon in HCOOH is
Detalhes da Resposta
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
Pergunta 12 Relatório
The experiment that showed that atoms have tiny positively charged nucleus was first carried out by
Detalhes da Resposta
Pergunta 13 Relatório
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
Detalhes da Resposta
Pergunta 14 Relatório
Detalhes da Resposta
The correct answer is 11.
pH = -log(H+) Or 14 - pOH
pOH = -log(0.001)
pOH = 3
pH = 14 - 3 = 11
Pergunta 15 Relatório
Use the diagram to answer this question.
The gas that can be used to demonstrate the experiment is
Detalhes da Resposta
Pergunta 16 Relatório
NH3(g) + HCl(s) → NH4Cl(s)
The entropy change in the system above is
Detalhes da Resposta
Pergunta 17 Relatório
The product obtained when a mixture of benzene vapour and hydrogen are passed over nickel catalyst at 180oC is
Detalhes da Resposta
Pergunta 18 Relatório
If the silver mirror test is positive, it indicates the presence of an
Detalhes da Resposta
Pergunta 19 Relatório
In the course of purifying water for town supply the water is passed through large settlings tanks, containing sodium aluminate (III) to remove
Detalhes da Resposta
Pergunta 20 Relatório
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]
Detalhes da Resposta
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
Pergunta 21 Relatório
The atom of an element X is represented as yzX . The basic chemical properties of X depend on the value of
Detalhes da Resposta
Pergunta 22 Relatório
A hydrocarbon X with a molar mass of 26 consists of 92.3% carbon. What is its molecular formular
Detalhes da Resposta
% 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
Pergunta 23 Relatório
Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of
Detalhes da Resposta
Pergunta 25 Relatório
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
Detalhes da Resposta
HCl + NaOH → NaCl + H2O
CAVA = NA/NB = (0.05 * 32)/(CB * 25)
∴ CB = (0.05 * 32)/25 = 0.064 mol dm-3
Pergunta 26 Relatório
Leads is used for making bullets and lead shots because of its
Detalhes da Resposta
Pergunta 28 Relatório
In recharging a lead-acid accumulator, the reaction at the cathode can be represented as
Detalhes da Resposta
Pergunta 31 Relatório
Diffusion is slowest in solid particles than in particles of liquid and gases because
Detalhes da Resposta
Pergunta 33 Relatório
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]
Detalhes da Resposta
Pergunta 34 Relatório
The uncovered raw food that is sold along major roads is likely to contain some amounts of
Detalhes da Resposta
Pergunta 37 Relatório
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]
Detalhes da Resposta
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
Pergunta 38 Relatório
Detalhes da Resposta
Pergunta 40 Relatório
Which of the following compounds of trioxonitrate (V) will decomposes to give dinitrogen (i) oxide and water when heated?
Detalhes da Resposta
Pergunta 41 Relatório
The vulcanizer's solution is prepared by dissolving rubber in
Detalhes da Resposta
Pergunta 42 Relatório
In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to
Detalhes da Resposta
Pergunta 43 Relatório
The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is
Detalhes da Resposta
Pergunta 44 Relatório
Reduction of nitroalkanes, nitrites and amides is a route for the preparation of
Detalhes da Resposta
Pergunta 45 Relatório
Insoluble salts can be prepared by
Detalhes da Resposta
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.
Pergunta 47 Relatório
Detergents are manufactured with straight hydrocarbon chains so as to make them
Detalhes da Resposta
Pergunta 49 Relatório
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]
Detalhes da Resposta
Relative molecular mass of NaCl = 23 + 35.5 = 55.5 g/mol
No. of mole of NaCl = 117/55.5 = 2.1 mol
