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Ajụjụ 1 Ripọtì
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]
Akọwa Nkọwa
Ajụjụ 2 Ripọtì
In recharging a lead-acid accumulator, the reaction at the cathode can be represented as
Ajụjụ 3 Ripọtì
Which of the following compounds of trioxonitrate (V) will decomposes to give dinitrogen (i) oxide and water when heated?
Ajụjụ 4 Ripọtì
If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to
Ajụjụ 5 Ripọtì
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]
Akọwa Nkọwa
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
Ajụjụ 6 Ripọtì
Use the diagram to answer this question.
The colour of the fountain water is
Akọwa Nkọwa
Ajụjụ 8 Ripọtì
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
Akọwa Nkọwa
Ajụjụ 9 Ripọtì
1111Na+10n→2411Na
The reaction above is an example of
Ajụjụ 10 Ripọtì
The experiment that showed that atoms have tiny positively charged nucleus was first carried out by
Ajụjụ 11 Ripọtì
In countries where the temperature falls below 273K, salt is always sprinkled on the icy road in order to
Ajụjụ 12 Ripọtì
The basicity of CH3COOH is
Ajụjụ 13 Ripọtì
The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is
Akọwa Nkọwa
Ajụjụ 14 Ripọtì
A catalyst speeds up the rate of chemical reaction by
Ajụjụ 15 Ripọtì
What is the IUPAC nomenclature of the compound NaCIO?
Ajụjụ 16 Ripọtì
Insoluble salts can be prepared by
Akọwa Nkọwa
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.
Ajụjụ 17 Ripọtì
Ajụjụ 18 Ripọtì
The oxidation state of carbon in HCOOH is
Akọwa Nkọwa
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
Ajụjụ 20 Ripọtì
When a few drops of water is added to a blue anhydrous cobalt (II) chloride, the colour changes to
Ajụjụ 22 Ripọtì
Chlorophyll obtained from given leaves of plant can be shown to be composed of more than one coloured component by the technique of
Akọwa Nkọwa
Ajụjụ 23 Ripọtì
A hydrocarbon X with a molar mass of 26 consists of 92.3% carbon. What is its molecular formular
Akọwa Nkọwa
% 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
Ajụjụ 24 Ripọtì
The most common ores of iron include
Ajụjụ 25 Ripọtì
The uncovered raw food that is sold along major roads is likely to contain some amounts of
Ajụjụ 26 Ripọtì
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]
Akọwa Nkọwa
Relative molecular mass of NaCl = 23 + 35.5 = 55.5 g/mol
No. of mole of NaCl = 117/55.5 = 2.1 mol
Ajụjụ 28 Ripọtì
The rate of a reaction usually decrease in the concentration of reactants because
Ajụjụ 29 Ripọtì
Reduction of nitroalkanes, nitrites and amides is a route for the preparation of
Ajụjụ 30 Ripọtì
Diffusion is slowest in solid particles than in particles of liquid and gases because
Ajụjụ 31 Ripọtì
Reduction of alkanonoes with LialH4 produces
Ajụjụ 32 Ripọtì
In the periodic table, the electrical and thermal conductivities are properties of elements that
Ajụjụ 33 Ripọtì
Choose the correct option from the structure above
Ajụjụ 34 Ripọtì
The IUPAC nomenclature for the structure above is
Ajụjụ 35 Ripọtì
The type of isomerism shown by cis- and trans- isomers is
Ajụjụ 36 Ripọtì
Leads is used for making bullets and lead shots because of its
Ajụjụ 37 Ripọtì
The diagram above represent the electron sub-level for
Ajụjụ 38 Ripọtì
Akọwa Nkọwa
The correct answer is 11.
pH = -log(H+) Or 14 - pOH
pOH = -log(0.001)
pOH = 3
pH = 14 - 3 = 11
Ajụjụ 39 Ripọtì
In the course of purifying water for town supply the water is passed through large settlings tanks, containing sodium aluminate (III) to remove
Akọwa Nkọwa
Ajụjụ 40 Ripọtì
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
Akọwa Nkọwa
HCl + NaOH → NaCl + H2O
CAVA = NA/NB = (0.05 * 32)/(CB * 25)
∴ CB = (0.05 * 32)/25 = 0.064 mol dm-3
Ajụjụ 41 Ripọtì
Use the diagram to answer this question.
The gas that can be used to demonstrate the experiment is
Ajụjụ 42 Ripọtì
If the silver mirror test is positive, it indicates the presence of an
Ajụjụ 44 Ripọtì
Ajụjụ 45 Ripọtì
The product obtained when a mixture of benzene vapour and hydrogen are passed over nickel catalyst at 180oC is
Ajụjụ 46 Ripọtì
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]
Akọwa Nkọwa
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
Ajụjụ 48 Ripọtì
300 cm3 of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume
Akọwa Nkọwa
P1V1= P2V2
800 * 300 = 650 * V2
V2 = (800 * 300)/650 = 369.23 cm3
Ajụjụ 49 Ripọtì
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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