Metallurgy · JEE Main previous year questions

Which of the reaction is suitable for concentrating ore by leaching process ?

1. A.$2{\text{Cu}}_2\text{S}+3{\text{O}}_2\to 2{\text{Cu}}_2\text{O}+2{\text{SO}}_2$
2. B.${\text{Fe}}_3{\text{O}}_4+\text{CO}\to 3\text{FeO}+{\text{CO}}_2$
3. C.${\text{Al}}_2{\text{O}}_3+2\text{NaOH}+3{\text{H}}_2\text{O}\to 2\text{Na}[{\text{Al(OH)}}_4]$
4. D.${\text{Al}}_2{\text{O}}_3+6\text{Mg}\to 6\text{MgO}+4\text{Al}$

Refining using liquation method is the most suitable for metals with :

1. A.Low melting point
2. B.High boiling point
3. C.High electrical conductivity
4. D.Less tendency to be soluble in melts than impurities

Match List-I with List-II $$\begin{array}{llll}& \text{List - I}& & \text{List - II}\\ \text{(A)}& \text{Concentration of gold ore}& \text{(I)}& \text{Aniline}\\ \text{(B)}& \text{Leaching of alumina}& \text{(II)}& \mathrm{NaOH}\\ \text{(C)}& \text{Froth stabiliser}& \text{(III)}& \mathrm{S}{\mathrm{O}}_2\\ \text{(D)}& \text{Blister copper}& \text{(IV)}& \mathrm{NaCN}\end{array}$$ Choose the correct answer from the options given below :

1. A.(A) - (IV), (B) - (III), (C) - (II), (D) - (I)
2. B.(A) - (IV), (B) - (II), (C) - (I), (D) - (III)
3. C.(A) - (III), (B) - (II), (C) - (I), (D) - (IV)
4. D.(A) - (II), (B) - (IV), (C) - (III), (D) - (I)

Given below are two statements : Statement I : According to Ellingham diagram, any metal oxide with higher $\Delta {\mathrm{G}}^{\circ }$ is more stable than the one with lower $\Delta {\mathrm{G}}^{\circ }$. Statement II : The metal involved in the formation of oxide placed lower in the Ellingham diagram can reduce the oxide of a metal placed higher in the diagram. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A.Both Statement I and Statement II are correct.
2. B.Both Statement I and Statement II are incorrect.
3. C.Statement I is correct but Statement II is incorrect.
4. D.Statement I is incorrect but Statement II is correct.

The role of depressants in 'Froth Flotation method' is to

1. A.selectively prevent one component of the ore from coming to the froth.
2. B.reduce the consumption of oil for froth formation.
3. C.stabilize the froth.
4. D.enhance non-wettability of the mineral particles.

Given below are two statements : Statement I : Sphalerite is a sulphide ore of zinc and copper glance is a sulphide ore of copper. Statement II : It is possible to separate two sulphide ores by adjusting proportion of oil to water or by using 'depressants' in a froth flotation method. Choose the most appropriate answer from the options given below :

1. A.Statement I is true but Statement II is false.
2. B.Both Statement I and Statement II are true.
3. C.Statement I is false but Statement II is true.
4. D.Both Statement I and Statement II are false.

The addition of silica during the extraction of copper from its sulphide ore :-

1. A.converts copper sulphide into copper silicate
2. B.converts iron oxide into iron silicate
3. C.reduces copper sulphide into metallic copper
4. D.reduces the melting point of the reaction mixture

In the leaching of alumina from bauxite, the ore expected to leach out in the process by reacting with NaOH is :

1. A.$\mathrm{Ti}{\mathrm{O}}_2$
2. B.$\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3$
3. C.ZnO
4. D.$\mathrm{Si}{\mathrm{O}}_2$

Match List I with List II : (Both having metallurgical terms) $$\begin{array}{llll}& \text{List - I}& & \text{List - II}\\ \text{(a)}& \text{Concentration of Ag ore}& \text{(i)}& \text{Reverberatory furnace}\\ \text{(b)}& \text{Blast furnace}& \text{(ii)}& \text{Pig iron}\\ \text{(c)}& \text{Blister copper}& \text{(iii)}& \text{Leaching with dilute NaCN solution}\\ \text{(d)}& \text{Froth floatation method}& \text{(iv)}& \text{Sulfide ores}\end{array}$$ Choose the correct answer from the options given below :

1. A.(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
2. B.(a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
3. C.(a)-(iv), (b)-(i), (c)-(iii), (d)-(ii)
4. D.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

The water having more dissolved ${\mathrm{O}}_2$ is :

1. A.boiling water
2. B.water at $80^{\circ }\mathrm{C}$
3. C.polluted water
4. D.water at $4^{\circ }\mathrm{C}$

Sulphide ion is soft base and its ores are common for metals. (a) Pb (b) Al (c) Ag (d) Mg

1. A.(a) and (c) only
2. B.(a) and (d) only
3. C.(a) and (b) only
4. D.(c) and (d) only

Match List - I with List - II. | List - I (Ore) | List - II (Element Present) | | :--- | :--- | | (a) Kernite | (i) Tin | | (b) Cassiterite | (ii) Boron | | (c) Calamine | (iii) Fluorine | | (d) Cryolite | (iv) Zinc | Choose the most appropriate answer from the options given below :

1. A.(a) $\to$ (i), (b) $\to$ (iii), (c) $\to$ (iv), (d) $\to$ (ii)
2. B.(a) $\to$ (iii), (b) $\to$ (i), (c) $\to$ (ii), (d) $\to$ (iv)
3. C.(a) $\to$ (ii), (b) $\to$ (i), (c) $\to$ (iv), (d) $\to$ (iii)
4. D.(a) $\to$ (ii), (b) $\to$ (iv), (c) $\to$ (i), (d) $\to$ (iii)

1. A.
2. B.
3. C.
4. D.

Within each pair of elements F & Cl, S & Se, and Li & Na, respectively, the elements that release more energy upon an electron gain are :

1. A.F, S and Li
2. B.Cl, Se and Na
3. C.Cl, S and Li
4. D.F, Se and Na

The refining method used when the metal and the impurities have low and high melting temperatures, respectively, is :

1. A.liquation
2. B.vapour phase refining
3. C.distillation
4. D.zone refining

1. A.only in the region a
2. B.in the region a and c
3. C.only in the region c
4. D.in the region a and b

The idea of froth floatation method came from a person X and this method is related to the process Y of ores. X and Y, respectively, are :

1. A.washer woman and concentration
2. B.fisher woman and concentration
3. C.washer man and reduction
4. D.fisher man and reduction

Match the refining methods (Column I) with metals (Column II). | Column I (Refining Methods) | Column II (Metals) | |---|---| | (I) Liquation | (a) Zr | | (II) Zone Refining | (b) Ni | | (III) Mond Process | (c) Sn | | (IV) Van Arkel Method | (d) Ga |

1. A.(I)-(c) ; (II)-(a) ; (III)-(b) ; (IV)-(d)
2. B.(I)-(c) ; (II)-(d) ; (III)-(b) ; (IV)-(a)
3. C.(I)-(b) ; (II)-(d) ; (III)-(a) ; (IV)-(c)
4. D.(I)-(b) ; (II)-(c) ; (III)-(d) ; (IV)-(a)

The ore that contains the metal in the form of fluoride is :

1. A.sphalerite
2. B.magnetite
3. C.malachite
4. D.cryolite

The one that is not a carbonate ore is :

1. A.siderite
2. B.bauxite
3. C.malachite
4. D.calamine

Assertion: For the extraction of iron, haematite ore is used. Reason: Haematite is a carbonate ore of iron.

1. A.Both the assertion and reason are correct and the reason is the correct explanation for the assertion.
2. B.Only the reason is correct.
3. C.Both the assertion and reason are correct, but the reason is not the correct explanation for the assertion.
4. D.Only the assertion is correct.

The Mond process is used for the

1. A.Extraction of Zn
2. B.extraction of Mo
3. C.Purification of Zr and Ti
4. D.Purification of Ni

The pair that does NOT require calcination is -

1. A.$\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3$ and $\mathrm{CaC}{\mathrm{O}}_3\cdot \mathrm{MgC}{\mathrm{O}}_3$
2. B.$\mathrm{ZnC}{\mathrm{O}}_3$ and CaO
3. C.ZnO and $\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3\cdot \mathrm{x}{\mathrm{H}}_2\mathrm{O}$
4. D.ZnO and MgO

The reaction that does NOT define calcination is :

1. A.$2\mathrm{C}{\mathrm{u}}_2\mathrm{S}+3{\mathrm{O}}_2\stackrel{\Delta }{\to }2\mathrm{C}{\mathrm{u}}_2\mathrm{O}+2\mathrm{S}{\mathrm{O}}_2$
2. B.$\mathrm{CaC}{\mathrm{O}}_3\cdot \mathrm{MgC}{\mathrm{O}}_3\stackrel{\Delta }{\to }\mathrm{CaO}+\mathrm{MgO}+2\mathrm{C}{\mathrm{O}}_2$
3. C.$\mathrm{ZnC}{\mathrm{O}}_3\stackrel{\Delta }{\to }\mathrm{ZnO}+\mathrm{C}{\mathrm{O}}_2$
4. D.$\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3\cdot \mathrm{X}{\mathrm{H}}_2\mathrm{O}\stackrel{\Delta }{\to }\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3+\mathrm{X}{\mathrm{H}}_2\mathrm{O}$

The ore that contains both iron and copper is :

1. A.Copper Pyrites
2. B.Malachite
3. C.Dolomite
4. D.Azurite