Chemistry
Choose the correct option:
(a) The metal other than aluminum, which has a strong affinity for oxygen is:
(A) Copper
(B) Magnesium
(C) Silver
(D) Gold
(b) A metallic oxide which cannot be reduced by normal reducing agents:
(A) Zinc oxide
(B) Magnesium oxide
(C) Copper (II) oxide
(D) Iron (III) oxide
Answer
(a) Magnesium
Reason — Oxides of highly active metals like potassium, sodium, calcium, magnesium and aluminium have great affinity for oxygen
(b) Magnesium oxide
Reason — Oxides of highly active metals like potassium, sodium, calcium, magnesium and aluminium have great affinity for oxygen and so cannot be reduced by common reducing agents like carbon, carbon monoxide or hydrogen.
They are obtained by electrolytic reduction of fused metallic salts (halides and oxides) using inert electrodes.
Related Questions
Which metal can be extracted from each one of the following ores:
(a) bauxite
(b) calamine
(c) haematite
Explain the following terms:
(a) ore
(b) gangue
Name:
(a) the processes involved in (i) dressing of the ores (ii) refining of the ores.
(b) two metallic oxides which cannot be reduced by carbon, carbon monoxide or hydrogen.
Give the principles of:
(a) Hydrolytic method
(b) Froth floatation process
(c) Electromagnetic separation