21
MCQ (Multiple Correct Answer)
Which of the following reactions occur during calcination?
A
$\mathrm{CaCO}_3 \longrightarrow \mathrm{CaO}+\mathrm{CO}_2$
B
$2 \mathrm{FeS}_2+\frac{11}{2} \mathrm{O}_2 \longrightarrow \mathrm{Fe}_2 \mathrm{O}_3+4 \mathrm{SO}_2$
C
$\mathrm{Al}_2 \mathrm{O}_3 \cdot x \mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{Al}_2 \mathrm{O}_3+x \mathrm{H}_2 \mathrm{O}$
D
$\mathrm{ZnS}+\frac{3}{2} \mathrm{O}_2 \longrightarrow \mathrm{ZnO}+\mathrm{SO}_2$
22
MCQ (Multiple Correct Answer)
For the metallurgical process of which of the ores calcined ore can be reduced by carbon?
A
Haematite
B
Calamine
C
Iron pyrites
D
Sphalerite
23
MCQ (Multiple Correct Answer)
The main reactions occurring in blast furnace during extraction of iron from haematite ore ............. .
A
$\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{CO} \longrightarrow 2 \mathrm{Fe}+3 \mathrm{CO}_2$
B
$\mathrm{FeO}+\mathrm{SiO}_2 \longrightarrow \mathrm{FeSiO}_3$
C
$\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{C} \longrightarrow 2 \mathrm{Fe}+3 \mathrm{CO}$
D
$\mathrm{CaO}+\mathrm{SiO}_2 \longrightarrow \mathrm{CaSiO}_3$
24
MCQ (Multiple Correct Answer)
In which of the following method of purification, metal is converted to its volatile compound which is decomposed to give pure metal?
A
Heating with stream of carbon monoxide
B
Heating with iodine
C
Liquation
D
Distillation
25
MCQ (Multiple Correct Answer)
Which of the following statements are correct?
A
A depressant prevents certain type of particle to come to the froth.
B
Copper matte contains $\mathrm{Cu}_2 \mathrm{S}$ and ZnS .
C
The solidified copper obtained from reverberatory furnace has blistered appearance due to evolution of $\mathrm{SO}_2$ during the extraction.
D
Zinc can be extracted by self-reduction.