2
MCQ (Single Correct Answer)
When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte contains
A
sulphides of copper (II) and iron (II)
B
sulphides of copper (II) and iron (III)
C
sulphides of copper (I) and iron (II)
D
sulphides of copper (I) and iron (III)
3
MCQ (Single Correct Answer)
Which of the following reactions is an example of autoreduction?
A
$\mathrm{Fe}_3 \mathrm{O}_4+4 \mathrm{CO} \longrightarrow 3 \mathrm{Fe}+4 \mathrm{CO}_2$
B
$\mathrm{Cu}_2 \mathrm{O}+\mathrm{C} \longrightarrow 2 \mathrm{Cu}+\mathrm{CO}$
C
$\mathrm{Cu}^{2+}(\mathrm{aq})+\mathrm{Fe}(\mathrm{s}) \longrightarrow \mathrm{Cu}(\mathrm{s})+\mathrm{Fe}^{2+}(\mathrm{aq})$
D
$\mathrm{Cu}_2 \mathrm{O}+\frac{1}{2} \mathrm{Cu}_2 \mathrm{~S} \longrightarrow 3 \mathrm{Cu}+\frac{1}{2} \mathrm{SO}_2$
4
MCQ (Single Correct Answer)
A number of elements are available in earth's crust but most abundant elements are ............. .
A
Al and Fe
B
Al and Cu
C
Fe and Cu
D
Cu and Ag
5
MCQ (Single Correct Answer)
Zone refining is based on the principle that ............ .
A
impurities of low boiling metals can be separated by distillation.
B
impurities are more soluble in molten metal than in solid metal.
C
different components of a mixture are differently adsorbed on an adsorbent.
D
vapours of volatile compound can be decomposed in pure metal.
6
MCQ (Single Correct Answer)
In the extraction of copper from its sulphide ore, the metal is formed by the reduction of $\mathrm{Cu}_2 \mathrm{O}$ with
A
FeS
B
CO
C
$\mathrm{Cu}_2 \mathrm{S}$
D
$\mathrm{SO}_2$