Chemistry 2010 Jamb Examination
Chemistry 2010 Jamb Examination
Question 11
Which of the following is used to hasten the ripening of fruit?
Ethene (ethylene) is a plant hormone that promotes fruit ripening; it is commonly used commercially to hasten ripening of climacteric fruits.
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Question 12
The final products of the reaction between methane and chlorine in the presence of ultraviolet light are hydrogen chloride and
Under extensive chlorination (excess chlorine & UV) methane can be fully substituted to give tetrachloromethane (CCl4) plus HCl as a product of each substitution step.
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Question 13
When iron is exposed to moist air, it gradually rusts. This is due to the formation of
Rust is hydrated iron(III) oxide (Fe2O3·nH2O), formed when iron corrodes in the presence of water and oxygen.
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Question 14
A compound gives an orange-red colour to non-luminous flame. This compound is likely to contain
Calcium (Ca2+) imparts an orange-red (brick red) colour to a non-luminous flame in flame tests.
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Question 15
Stainless steel is used for making
Stainless steel is corrosion-resistant and strong, making it suitable for making tools; it is not typically magnetic enough for magnets nor commonly used for coins/medals or fine clock moving parts where other alloys are preferred.
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Question 16
The residual solids from the fractional distillation of petroleum are used as
Heavy residuals (like bitumen) are used for coatings (e.g., road surfacing, pipe coatings). They are also feedstock for further processing but the listed best match is coatings of pipes.
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Question 17
CH3(CH2)3CHC2H5
           |
         C3H7
The IUPAC nomenclature of the compound above is
           |
         C3H7
The IUPAC nomenclature of the compound above is
Number the longest chain and locate the substituent so the substituent gets the lowest possible number. The correct name given the structure (branch at carbon 3 with a propyl group) is 3-propylheptane as stated.
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Question 18
The graph above demonstrate the effect of
The typical graph showing increased rate with increased available surface (e.g., powdered vs lump reactant) demonstrates the effect of surface area on reaction rate.
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Question 19
2H2(g) + O2(g) → 2H2O(g) ΔH = -ve
What happens to the equilibrium constant of the reaction above if the temperature is increased?
What happens to the equilibrium constant of the reaction above if the temperature is increased?
The reaction is exothermic (ΔH negative). Increasing temperature shifts the equilibrium toward reactants (Le Chatelier), so the equilibrium constant K decreases.
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Question 20
To a solution of an unknown compound, a little dilute tetraoxosulphate (VI) acid was added with some freshly prepared iron (II) tetraoxosulphate (VI) solution. The brown ring observed after the addition of a stream of concentrated tetraoxosulphate (VI) acid confirmed the presence of
The brown ring test (formation of the brown ring at the junction) is a characteristic test for nitrite ions (NO2-), producing a nitrosyl ferrous complex.