Search SchoolNGR

Monday, 20 April 2026
Register . Login

(a) List two substances that can be used in the laboratory to (i) dry hydrogen; (ii) ...

(a) List two substances that can be used in the laboratory to
(i) dry hydrogen;
(ii) remove carbon (IV) oxide from a sample of air;
(iii) convert hot copper (II) oxide to copper;
(iv) prepare zinc chloride by the action of dilute HCI.

(b)(i) Name two alloys which contain lead.
(ii) State and explain what is observed on bubbling H\(_2\)S into a solution of Pb(NO)\(_2\).
(iii) A metal M exists as a silvery white solid at temperatures above 18°C and as a grey solid below 18°C.
I. name the phenomenon exhibited by M.
II. What term is used to describe the temperature given as 18°C in this case?

(c)(i) Write an equation for the action of heat on each of the following compounds:
I. AgNO\(_3\)
II. (NH4)\(_2\)CO\(_3\).

(ii) Copy and complete the table below
Metal Name of main ore Method of extraction One major use Haematite
Haematite
Electrolysis of molten oxide




Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
    Correct Answer: Option n
    Explanation:
    (a)(i) Fused calcium chloride and concentrated tetraoxosulphate (VI) acid.
    (ii) Ca(OH)\(_2\), NaOH.
    (iii) Hydrogen and carbon (II) oxide
    (iv) Zn metals, zinc trioxocarbonate
    (IV), zinc oxides.

    (b)(i) Soft solder for welding and plumbing and type metal for printing.
    (ii) a black precipitate of PbS\(_{(s)}\) is deposited
    (iii)(i) Polymorphism
    (ii) Transition temperature

    (c)(i) 2AgNO\(_{3(s)}\) --> 2Ag\(_{(s)}\) + O\(_2\) + 2NO\(_{2}\).
    Lustrous Brown white
    (ii) NH\(_4\)CO\(_3\) -> 2NH\(_3\) + CO\(_2\) + H\(_2\)O.

    (iii)
    Metal Name of main ore Method of extraction One major use Iron
    Iron Haematite Reaction process Constfuction of vehicles
    Aluminium Bauxite Electrolysis of molten oxide cables, paints, cooking utensils



    Share question on: