JAMB UTME - Chemistry - 2008
Question 1 Report
The experiment that showed that atoms have tiny positively charged nucleus was first carried out by
Answer Details
Question 3 Report
Insoluble salts can be prepared by
Answer Details
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.
Question 4 Report
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]
Answer Details
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
Question 5 Report
When a few drops of water is added to a blue anhydrous cobalt (II) chloride, the colour changes to
Question 6 Report
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
Answer Details
HCl + NaOH → NaCl + H2O
CAVA = NA/NB = (0.05 * 32)/(CB * 25)
∴ CB = (0.05 * 32)/25 = 0.064 mol dm-3
Question 7 Report
The atom of an element X is represented as yzX . The basic chemical properties of X depend on the value of
Answer Details
Question 10 Report
Diffusion is slowest in solid particles than in particles of liquid and gases because
Question 11 Report
Answer Details
The correct answer is 11.
pH = -log(H+) Or 14 - pOH
pOH = -log(0.001)
pOH = 3
pH = 14 - 3 = 11
Question 12 Report
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]
Answer Details
Question 13 Report
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]
Answer Details
Relative molecular mass of NaCl = 23 + 35.5 = 55.5 g/mol
No. of mole of NaCl = 117/55.5 = 2.1 mol
Question 14 Report
Reduction of nitroalkanes, nitrites and amides is a route for the preparation of
Question 16 Report
In the periodic table, the electrical and thermal conductivities are properties of elements that
Answer Details
Question 18 Report
Detergents are manufactured with straight hydrocarbon chains so as to make them
Answer Details
Question 19 Report
1111Na+10n→2411Na
The reaction above is an example of
Question 20 Report
A hydrocarbon X with a molar mass of 26 consists of 92.3% carbon. What is its molecular formular
Answer Details
% 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
Question 21 Report
The oxidation state of carbon in HCOOH is
Answer Details
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
Question 23 Report
In recharging a lead-acid accumulator, the reaction at the cathode can be represented as
Question 24 Report
300 cm3 of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume
Answer Details
P1V1= P2V2
800 * 300 = 650 * V2
V2 = (800 * 300)/650 = 369.23 cm3
Question 25 Report
Answer Details
Question 26 Report
Use the diagram to answer this question.
The gas that can be used to demonstrate the experiment is
Question 27 Report
Choose the correct option from the structure above
Question 29 Report
The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is
Answer Details
Question 30 Report
The rate of a reaction usually decrease in the concentration of reactants because
Answer Details
Question 31 Report
In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to
Question 32 Report
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]
Answer Details
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
Question 33 Report
If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to
Answer Details
Question 34 Report
If the silver mirror test is positive, it indicates the presence of an
Question 36 Report
Reduction of alkanonoes with LialH4 produces
Question 37 Report
Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of
Answer Details
Question 38 Report
Use the diagram to answer this question.
The colour of the fountain water is
Answer Details
Question 39 Report
NH3(g) + HCl(s) → NH4Cl(s)
The entropy change in the system above is
Answer Details
Question 40 Report
Answer Details
Question 41 Report
The uncovered raw food that is sold along major roads is likely to contain some amounts of
Answer Details
Question 42 Report
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
Answer Details
Question 44 Report
The product obtained when a mixture of benzene vapour and hydrogen are passed over nickel catalyst at 180oC is
Question 45 Report
Which of the following compounds of trioxonitrate (V) will decomposes to give dinitrogen (i) oxide and water when heated?
Answer Details
Question 48 Report
The IUPAC nomenclature for the structure above is
Question 49 Report
In the course of purifying water for town supply the water is passed through large settlings tanks, containing sodium aluminate (III) to remove
Answer Details
