Hint

Explanation

Hint

Hint

MnO^2- = -2
X+(-2×2) =-2
X + -4 = -2
X = +2
MnO4 = -1
X+(-2×4)=-1
X = -1+8
X=+7 (B)

Hint

Explanation.

Hint

Saturated hydrocarbons have single bond around its carbon, so they exhibit SP3 hybridization (A)

Hint

CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂
Ethyne (ethylene) produced when passed through oxygen give oxyacetylene flame, used for welding (D)

Hint

M(OH)₃ = 78gmol^-1
M+(16+1)3 = 78
M+(17×3) = 78
M=78—51 = 27(D)

Hint

E.g. X → X + e (loss of electron) (A)

Hint

The reaction is acid catalysed and reversible produce methylethanoate (ester) in the process called esterification (B)

Hint

^A_ZX when A = 17 mass number
X = 8 atomic number
Atomic No. = no. of proton + no. of neutron = 17–8 = 9 (D)

Hint

Ethylene (C2H4) and acetylene (C2H2). All alkynes with a terminal triple bond undergo substitution reaction with CuCl
to give reddish brown colouration of Cu2C2 (B)

Hint

M + 2HCI → MCI₂ + H₂
1 mole: 2 mole 1mole : 1mole
No. of mole = 0.224.m⁴
22.4dm
= 0.01 mole of hydrogen gas
Since 1 mole of H₂ is liberated by 1mole of M 0.0lmole of H₂ will liberate 1mole of M Mass of M = 40×0.01 = 0.4g (C)

Hint

An element with atomic number 12 is metallic divalent and a reducing agent, ionize by losing 2 electrons to combine with
non-metals to form electrovalent bond (B)

Hint

Oxygen is 21% of oxygen
% oxygen = Vol of oxygen x 100
Total Vol of air
21%= 10cm³ x 100
Total volume of air
Total vol. of air = (10cm³ x 100%) /21%

=47.61

=50(C)

Hint

Nicotine is a substance in cigarette which makes
difficult to make one stop smoking. This can be
derived by burning. Options B,C,D will not reduce
this nicotine

Hint

Crystallization is required the most in industries
where the purity of their products is important e.g in
the manufacture of drugs and in sugar production.
Options B,C and D do not undergo crystallization

Hint

Iron is galvanized with zinc covering to protect it
against corrosion. Option A, B, D are the main
reasons iron is galvanized

Hint

Washing under pressure is an action in the industrial
production of H. Options B,C,D will not yield Co
and H

Hint

Washing under pressure is an action in the industrial
production of H. Options B,C,D will not yield Co
and H

Hint

The ozone layer or ozone shield refers to a region of
Earth’s stratosphere that absorbs most of the Sun’s
ultraviolet (UV) radiation. It contains high
concentrations of ozone (O3) relative to other parts of
the atmosphere, although still very small relative to
other gases in the stratosphere

Hint

Vulcanizer is the removal of double bend in a
chemical reaction. Option A,B,D can not be removed
by vulcanizer

Hint

HeSO4
is the acid used in the electrolysis of water.
Option A,B,D are concentrated acid and they will
react with the water

Hint

Efflorescence is a process of long exposure to the
atmosphere which favors salt loss of water. Options
B, C, D are not related to loss of water

Hint

Ozone means Oz as the atomicity is 3. Option A,B,D
cannot give ozone because their atomicity is not 3

Hint

Helium has the greatest ionization energy because
they are less stable. Options B,C,D have low
ionization energy because one more stable and do not
react easily

Hint

Vander Waals are the weakest attractive forces that
exist between two molecules. Option A,B,C are not
weak forces because the force attraction that exist
between their interested molecule are very strong

Hint

Sulphur is an element that burns with a strongly
explosive smell, as a result it is explosive smell

Hint

Rays travels in straight lines and finds its way
through any opening available. It could be refracted,
reflected or transmitted based on any obstacle.
Option A,B,C are not the reason why the cathode are
coasted shadows

Hint

Sodium hydrogen trionocarbonate iv is the only
distinguishing reagent between ethanoic and ethanol.
Option A, B, D are not conspicuous in distinguishing
between ethanoic and ethanol

Hint

Discharge tube with central cathode is an apparatus
for producing cathode rays and positive rays. Option
A,B,C will not yield cathode rays and positive rays

Hint

Calcium is the only metal that burn with brick red
flame. Option A,C,D will not burn with brick red
flame rather burn with brick blue flame

Hint

Concentrated sodium chloride solution will the
solubility of soap along the course of soap
production. Options A,C,D are not appropriate

Hint

Kerosene is only liquid that will dissolve fat. Option
A,B,D will not dissolve fat because of their chemical
composition

Hint

A is the correct answer. Tartaric acid is found in
cream of tartar, which is used in cooking candies and
frostings for cakes. Tartaric acid is also found in
baking powder, where it serves as the source of acid
that reacts with sodium bicarbonate (baking soda)

Hint

V = 1/P
cross multiply
K = VP
V1P1 = V2V2
For a fixed amount of an ideal gas kept at a fixed
temperature, pressure and volume are inversely
proportional. Or Boyle’s law is a gas law, stating that
the pressure and volume of a gas have an inverse
relationship, when temperature is held constant.
The equations supports only Boyle’s law. Option
A,C,D are not in support of the equation…

Hint

V1 ÷ T1 = V2 ÷ T2
T1 = 3 × 273 = 276k
T2 = 18 + 273 = 291k
V1 = 92cm3
V2 = ?
V2 = (V1T2) ÷ T1 = (92 × 291) ÷ 276
= 97.0cm3

Hint

2.0 mole of Q3+ ions require the largest quantity of
electricity for discharge at an electric. option B,C,D
are all carrying a smaller quantity of electricity which
not be proven for ant discharge

Hint

Fe displaces hydrogen from hot alkaline solution.
Options B,C,d will not displace hydrogen

Hint

Only primary alkanols undergo oxidation to produce
alkanoic acid. Option A,B,C will not produce
alkanoic acid

Hint

Rare gases are stable because they have duplet or
octet electronic configurations in the outermost shells
in their atoms, as a result they don’t go into solution
easily. option A, B, Dare not because they go into
solution easily (unstable)

Hint

Coal is a major senses of oxide of nitrogen. Option
B,C, D do not contribute to the anode Nitrogen
either. They are sources of oxides of carbon of
sulphur etc

Hint

The oxidation number is from h to O as a result of
release of sulphur. Option B, C, D are not the actual
oxidation number for copper

Hint

The number of isomers C6H14 cm is 5. it will not
form options A,C, D

Hint

Salt is a chemical used for varieties of purposes, so
it’s not part of matter, Atom being the smallest part of
molecule and ion are charge which are part of matter

Hint

Fractionating column contains petrol with different
densities.

Hint

2NaOH + H2SO4 → Na2SO4 + 2H2O
CaVa) ÷ (CbVb) = ratio of acid / ratio of base
0.5Va ÷ (0.1 × 20) = ½
Va = 2.0cm3

Hint

C = 40%, 40/12 = 3.33
H = 6.7%, 6.7/1 = 6.7
O = 53.3%, 53.3/16 = 3.33
C = 3.33/3.33 = 1
H = 6.7/3.33 = 2
O = 3.33/3.33 = 1
(CH2O)n = 180
(12 + 2 + 16)n = 180
30n = 180
n = 6
= C6H12O6

Hint

The oxidation state of K2Cr2O7 is +6. option A,C,D
are the oxidation state of other elements like O7,C14,
etc.

Hint

Na, Mg, s and Ar one elements that belong to third
period of the periodic table. Option A,B,C belong to
the other period in the periodic table, second period

Hint

No entropy change because the sugar will not change
the chemical equivalent of the tea. Options A,B,D are
not appropriate because they will change the
chemical combination of the tea

Hint

Entropy s is a measure of the degree of disorder or
randomness of a substance. The entropy charge in the
system is negative. Options B, C, D will not give
negative but the result into positive

Hint

Biodegradable because the straight hydrocarbons are
natural and slightly soluble in water. Options A,C,D
do not have strength hydrocarbon chains and they
could harm the environment if they are made with the
detergent

Hint

Oxide of sulphur is formed as a result of acid rain.
Options A,B, D are not formed as a result of the
pressure of acid

Hint

Calcium hydrogen trionocarbonate (iv) will cause the
forming of kettles whenever water is present. Options
A, C, D will not react under the presence of water

Hint

In chemical change a new substance is formed while
in physical change no new substance is formed.
Options A,B,C are all properties of a physical change

Hint

AlCl3
will give a precipitate when treated with
solution. Option B,C,D will not give a precipitate
when treated with NaOH solution

Hint

Alloy is a metal that consist of two or more metals
mixed together e.g. is mass which is an alloy of
copper and zinc. Are not prepared with option A,B,C,
and the do not result in mixture and metals together

Hint

Salt is good chemical agent that lowers the melting of
an ice only it temperature below 0°C options B,C,D
will not have the melting point except is above the 0°
C. only salt does that.

Hint

CH4(g)
+ 2O2(g)
→ 2H2O(g)
1 volume of methane will react with 90cm3
of
oxygen at S.T.P

Hint

Oxygen is a substance that is used to remove
impurities from pig iron. Options B, C, D will be
effective in removing impurities positive]

Hint

Carbon concentration of 4 will not give a precipitate
heating. Option B,C,D will not be dehydrated

Hint

Rare gases are stable because they have duplet or
octet electronic configurations in the outermost shells
in their atoms, as a result they don’t go into solution
easily. option A, B, Dare not because they go into
solution easily (unstable)

Hint

Ethanol has the molecular formula C2H6O. Option
A, C, D are not because their molecular are not
different

Hint

The bubble remain the same because entropy favors
the mixture as it is the degree of randomness or
disorderliness. Option B,C,D will not favors the
entropy

Hint

[H+][OH−] = 10 − 4
[H+] =10 − 14 ÷ [OH+]
=10 −14 ÷ (1 × 10 − 3) = 10 − 11
pH = − log10[H+ ]
= − log10[10 − 11] = − 1 × −11
log10[10 − 11] = 1
= − 1 × 11 × 1
= − 11

Hint

A decrease in pressure will result in the breaking or
splitting of a larger molecule into a simpler ones.
Options A, B, D are not in conformance to the

Hint

Chlorine turns a damp starch iodide paper into dark
blue or blue black.

Hint

Let the relative abundance of the energy with mass
37 be
Total relative abundance of the isotope of mass
359100-k)
Total mass of isotope of mass 37-37x, while that of
35-359(100x)
-37x + 3500 − 35 − 35.5
-37x + 3500 − 35n − 35.5
Mean mass of chlorine atom − (2n + 3500)/ ÷ 100
= 35.5
2x + 3500 − 3550yx = 50/2

Hint

Methane CH4.A. is the principal and commercial
constituent natural gas. Option B,C,D are also
constituent of natural gas but they are not commercial
and of economic importance

Hint

2VD = Rmm
VD = Vapour Density, Rmm = relative
2 × 20 − 40 molecular mass
Mole of carbon − 36/12
= 3
Mole of H2 = 40 − 36
= 4
The compound contains 3mole of carbon and 4
hydrogen

Hint

40H − 4e → 2H2O + O2is the reaction of sun at the
anode in the electrolysis of CuSO4 (g) using
platinum particles. Option A,C,D are not formed as a
result of the equation

Hint

In SO4. The state of oxygen oxidation number is -2.
Options A,C,D do not belong to the oxidation state in
SO4

Hint

In the industrial of brine carbon is the anode while
mercury is the cathode. Options of A, B, C are not
used in brine solution because they are alloy of
mercury

Hint

One molecule of CaCO has 1Ca, 1C and 30 atom
relative molecular mass of CaCO3
1 × Ar of Ca +1 × Ar of C +3 × Ar of O
(1 × 40 + 1 × 12 + 3 × 1)
40 + 12 + 48
=100
Option A,C and D will not give 100

Hint

Hydrogen and carbon (ii) oxide will be formed when
red steam is passed ever red-hot carbon. Option
A,B,D are not produced through this process

Hint

the vending machine is a retails machine that release
the product to the tune of the amount of money
slotted into the machine and the product indicated by
the consumer.

Hint

the marketing department does public relations i.e the
public relations department is part of the marketing
department

Hint

the securities and exchange commission is the
regulatory apex organization of the Nigerian capital
market.

Hint

it is joint stock Company that prepare memorandum
of association during the course of registering the
company it is also known as Limited Liability
Company.

Hint

As a jobber takes title to the goods and has authority
to buy and sell or behalf of another