141. Which of the following ore is concentrated by chemical leaching method?
A
Cinnabar
B
Argentite
C
Copper pyrites
D
Galena
Answer :
Argentite
142.
The mineral carnallite contains $$\underline {\left( {\text{i}} \right)} $$ and $$\underline {\left( {{\text{ii}}} \right)} $$ metals. $$\underline {\left( {{\text{iii}}} \right)} $$ is purified by cupellation and $$\underline {\left( {{\text{iv}}} \right)} $$ is purified by distillation.
| (i) | (ii) | (iii) | (iv) | |
| (a) | calcium | zinc | mercury | tin |
| (b) | calcium | magnesium | zinc | lead |
| (c) | potassium | calcium | copper | mercury |
| (d) | magnesium | potassium | silver | mercury |
A
(a)
B
(b)
C
(c)
D
(d)
Answer :
(d)
143. Calcium is obtained by the
A
roasting of limestone
B
electrolysis of solution of calcium chloride in $${H_2}O$$
C
electrolysis of molten anhydrous calcium chloride
D
reduction of calcium chloride with carbon
Answer :
electrolysis of molten anhydrous calcium chloride
144. The following reactions take place in the blast furnace in the preparation of impure iron. Identify the reaction pertaining to the formation of the slag.
A
$$F{e_2}{O_3}\left( s \right) + 3\,CO\left( g \right) \to 2\,Fe\left( l \right) + 3\,C{O_2}\left( g \right)$$
B
$$CaC{O_3}\left( s \right) \to CaO\left( s \right) + C{O_2}\left( g \right)$$
C
$$CaO\left( s \right) + Si{O_2}\left( s \right) \to CaSi{O_3}\left( s \right)$$
D
$$2C\left( s \right) + {O_2}\left( g \right) \to 2\,CO\left( g \right)$$
Answer :
$$CaO\left( s \right) + Si{O_2}\left( s \right) \to CaSi{O_3}\left( s \right)$$
145. Which of the following metals is extracted using a silica lined convertor?
A
$$Mg$$
B
$$Al$$
C
$$Cu$$
D
$$Zn$$
Answer :
$$Cu$$
146. Which of the following statements is correct about the role of collectors added during froth floatation process?
A
Collectors enhance the non-wettability of ore particles.
B
Collectors enhance the wettability of gangue particles.
C
Collectors help in separating two sulphide ores present in the mixture.
D
Collectors help ore particles to settle down below the froth.
Answer :
Collectors enhance the non-wettability of ore particles.
147. Oxidation states of the metal in the minerals haematite and magnetite, respectively, are
A
II, III in haematite and III in magnetite
B
II, III in haematite and II in magnetite
C
II in haematite and II, III in magnetite
D
III in haematite and II, III in magnetite
Answer :
III in haematite and II, III in magnetite
148. The form of iron obtained from blast furnace is :
A
Steel
B
Cast Iron
C
Pig Iron
D
Wrought Iron
Answer :
Cast Iron
149.
Complexes formed in the following methods are
(i) Mond's process for purification of nickel.
(ii) Removal of lead poisoning from the body.
(iii) Cyanide process for extraction of silver.
(iv) Froth flotation process for separation of $$ZnS$$ from galena ore by using depressant.
| (i) | (ii) | (iii) | (iv) | |
| (a) | $$Ni{\left( {CO} \right)_4}$$ | $${\left[ {Pb\left( {EDTA} \right)} \right]^{2 - }}$$ | $${\left[ {Ag{{\left( {CN} \right)}_2}} \right]^ - }$$ | $$\left[ {Zn{{\left( {CN} \right)}_2}} \right]$$ |
| (b) | $$Ni{\left( {CO} \right)_4}$$ | $${\left[ {Pb\left( {EDTA} \right)} \right]^{2 - }}$$ | $${\left[ {Ag{{\left( {CN} \right)}_2}} \right]^ - }$$ | $${\left[ {Zn{{\left( {CN} \right)}_4}} \right]^{2 - }}$$ |
| (c) | $$Ni{\left( {CO} \right)_6}$$ | $${\left[ {Pb\left( {EDTA} \right)} \right]^{4 - }}$$ | $${\left[ {Ag{{\left( {CN} \right)}_2}} \right]^ - }$$ | $${\left[ {Zn{{\left( {CN} \right)}_6}} \right]^{4 - }}$$ |
| (d) | $$Ni{\left( {CO} \right)_4}$$ | $${\left[ {Pb\left( {EDTA} \right)} \right]^{2 - }}$$ | $${\left[ {Ag{{\left( {CN} \right)}_4}} \right]^{3 - }}$$ | $${\left[ {Zn{{\left( {CN} \right)}_4}} \right]^{2 - }}$$ |
A
(a)
B
(b)
C
(c)
D
(d)
Answer :
(b)
150.
In the following Ellingham diagram, $$X, Y$$ and $$Z$$ represent graphs for metal oxides. Select the correct option before point $$A.$$
A
$$Y$$ will reduce oxide of $$Z.$$
B
$$Y$$ will reduce oxide of $$X.$$
C
$$Z$$ will reduce oxide of $$X.$$
D
$$Z$$ will reduce oxide of $$Y.$$
Answer :
$$Y$$ will reduce oxide of $$Z.$$