d and f Block Elements — Page 12 | JEE Chemistry

Q111

Which of the following methods are not used to refine any metal? A. Liquation B. Calcination C. Electrolysis D. Leaching E. Distillation Choose the correct answer from the options given below:

A B and D only

B A, B, D and E only

C B, D and E only

D A, C and E only

Correct Answer

Option A

Solution

Leaching and calcination are the processes which are involved in the extraction of the metals.

Liquation, Electrolytic refining, Distillation are used in the refining or purification of metal.

Q112

Given below are two statements : Statement I : The choice of reducing agents for metals extraction can be made by using Ellingham diagram, a plot of

\Delta

G vs temperature. Statement II : The value of

\Delta

S increases from left to right in Ellingham diagram. In the light of the above statements, choose the most appropriate answer from the options given below :

A Both Statement I and Statement II are true

B Statement I is false but Statement II is true

C Both Statement I and Statement II are false

D Statement I is true but Statement II is false

Correct Answer

Option D

Solution

Given Statement I is true as in a number of processes, one element is used to reduce the oxide of another metal.

Any element will reduce the oxide of other metal which lie above it in the Ellingham diagram because the free energy change will become more negative.

Given Statement II is false as the value of

\Delta

S is decreases from left to right in Ellingham diagram.

Q113

Which refining process is generally used in the purification of low melting metals?

A Chromatographic method

B Liquation

C Electrolysis

D Zone refining

Correct Answer

Option B

Solution

Liquation method is used to purify those impure metals which has lower melting point than the melting point of impurities associated.

$\therefore$ This method is used for metal having low melting point.

Q114

Which one of the following reactions does not occur during extraction of copper?

A

\mathrm{2FeS + 3{O_2} \to 2FeO + 2S{O_2}}

B

\mathrm{FeO + Si{O_2} \to FeSi{O_3}}

C

\mathrm{CaO + Si{O_2} \to CaSi{O_3}}

D

\mathrm{2C{u_2}s + 3{O_2} \to 2C{u_2}O + 2S{O_2}}

Correct Answer

Option C

Solution

\begin{aligned} & \mathrm{CuFeS}_2+\mathrm{O}_2 \stackrel{\text{ Partial roasting }}{\longrightarrow} \\\\ & \mathrm{Cu}_2 \mathrm{~S}+\mathrm{FeO}+\mathrm{SO}_2+\underset{\text{ very small }}{\mathrm{FeS}}+\underset{\text{ very small }}{\mathrm{Cu}_2 \mathrm{O}} \\\\ & \mathrm{Cu}_2 \mathrm{~S}+\mathrm{O}_2 \rightarrow \mathrm{Cu}_2 \mathrm{O}+\mathrm{SO}_2 \\\\ & \mathrm{FeS}+\mathrm{O}_2 \rightarrow \mathrm{FeO}+\mathrm{SO}_2 \\\\ & \mathrm{FeO}+\mathrm{SiO}_2 \rightarrow \mathrm{FeSiO}_3 \end{aligned}

No formation of calcium silicate $\left(\mathrm{CaSiO}_3\right)$ in extraction of $\mathrm{Cu}$ .

Q115

The metal which is extracted by oxidation and subsequent reduction from its ore is :

A Al

B Cu

C Ag

D Fe

Correct Answer

Option C

Solution

Ag is first extracted by oxidation and then the subsequent reduction is carried out to obtain

\begin{aligned} & \begin{aligned} 4 \mathrm{Ag}+8 \mathrm{NaCN}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2} \end{aligned} \stackrel{\text{ Oxidation }}{\longrightarrow} 4 \mathrm{Na}\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]+4 \mathrm{NaOH} \\\\ & 2 \mathrm{Na}\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]+\mathrm{Zn} \stackrel{\text{ reduction }}{\longrightarrow} \mathrm{Na}_{2}\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]+2 \mathrm{Ag} \end{aligned}

Q116

Match with . ^{3+}$

List - I		List - II
(B)	$\mathrm{V}^{2+}$	(I)	3.87
(C)	$\mathrm{Ni}^{2+}$	(II)	0.00
(D)	$\mathrm{Sc}^{3+}$	(III)	1.73
()		(IV)	2.84

A

\mathrm{(A) -(III}),(\mathrm{B})-(\mathrm{I}),(\mathrm{C})-(\mathrm{IV}),(\mathrm{D})-(\mathrm{II})

B

(\mathrm{A})-(\mathrm{II}),(\mathrm{B})-(\mathrm{IV}),(\mathrm{C})-(\mathrm{I}),(\mathrm{D})-(\mathrm{III})

C

(\mathrm{A})-(\mathrm{III}),(\mathrm{B})-(\mathrm{I}),(\mathrm{C})-(\mathrm{II}),(\mathrm{D})-(\mathrm{IV})

D

(\mathrm{A})-(\mathrm{IV}),(\mathrm{B})-(\mathrm{II}),(\mathrm{C})-(\mathrm{III}),(\mathrm{D})-(\mathrm{I})

Correct Answer

Option A

Solution

\begin{array}{ll} \mathrm{Sc}^{+3}=3 \mathrm{~d}^{\circ} & \therefore \mu_{\text{spin }}=0 \\ \mathrm{~V}^{+2}=3 \mathrm{~d}^3 & \therefore \mu_{\text{spin }}=3.87 \text{ B.M. } \\ \mathrm{Ni}^{+2}=3 \mathrm{~d}^8 & \therefore \mu_{\text{spin }}=2.84 \text{ B.M. } \end{array}

$\mathrm{Ti}^{+3}=3 \mathrm{~d}^1 \quad \therefore \mu_{\mathrm{spin}}=1.73 \mathrm{~B} . \mathrm{M}$

Q117

Match the ores (column A) with the metals (column B) : .tg .tg (Column A) ores (Column B) Metals

List - I		List - II
(a)	Zinc	(I)	Siderite
(b)	Copper	(II)	Kaolinite
(c)	Iron	(III)	Malachite
(d)	Aluminium	(IV)	Calamine

A (I)-(c); (II)-(d); (III)-(b); (IV)-(a)

B (I)-(a); (II)-(b); (III)-(c); (IV)-(d)

C (I)-(b); (II)-(c); (III)-(d); (IV)-(a)

D (I)-(c); (II)-(d); (III)-(a); (IV)-(b)

Correct Answer

Option A

Solution

Siderite : FeCO3 Kaolinite : Al2(OH)4Si2O5 Malachite : CuCO3 .

Cu(OH)2 Calamine : ZnCO3 Note : ( Remember all those ores names.

Any one of those can be asked in the exam.)

Oxides Ores : (1) ZnO - Zincite (2) Fe2O3 - Haematite (3) Fe3O4 - Magnetite (FeO + Fe2O3 mixture) (4) Fe2O3 .

3H2O - Limonite (5) MnO2 - Pyrolusite (6) Cu2O - Cuprite or Ruby Copper (7) TiO2 - Rutile (8) FeCr2O4 - Chromite (FeO + Cr2O3) (9) FeTiO3 - Illmenite (FeO + TiO2) (10) Na2B4O7 .

10H2O - Borax or Tincal (11) U3O8 - Pitch Blende (12) SnO2 - Tin Stone or Cassiterite (13) Ca2B6O11 .

5H2O - Colemanite (2 Cao + 3 B2O3) (14) Al2O3 .

2H2O - Bauxite (15) Al2O3 .

H2O - Diaspore (16) Al2O3 - Corundum Sulphides Ores : (1) ZnS - Zinc Blende or Sphalerite (2) PbS - Galena (3) Ag2S - Argentite or Silver Glance (4) HgS - Cinnabar (5) Cu2S - Chalcocite or Copper glance (6) CuFeS2 - Copper pyrites or Chalco pyrites (Cu2S + Fe2S3 mixture) (7) FeS2 - Iron pyrites or Fool's Gold (8) 3Ag2S .

Sb2S2 - Pyrargyrite or ruby silver Halides Ores : (1) NaCl - Rock Salt (2) KCl - Sylvine (3) Na3AlF6 - Cryolite [3NaF + AlF6] (4) CaF2 - Fluorspar (5) KCl .

MgCl2 .

6H2O - Carnalite (6) AgCl - Horn Silver Carbonates Ores : (1) CaCO3 - Limestone (2) MgCO3 - Magnesite (3) CaCO3 .

MgCO3 - Dolomite (4) ZnCO3 - Calamine (5) PbCO3 - Cerrusite (6) FeCO3 - Siderite (7) CuCO3 .

Cu(OH)2 or Cu2CO3(OH)2 - Malachite or Basic Copper Carbonates (8) 2 CuCO3 .

Cu(OH)2 - Azurite Sulphates Ores : (1) CuSO4 .

2H2O - Gypsum (2) MgSO4 .

7H2O - Epson Salt (3) Na2SO4 .

10 H2O - Glauber's Salt (4) PbSO4 - Anglesite (5) ZnSO4 .

7H2O - White Vitriol (6) FeSO4 .

7H2O - Green Vitriol (7) CuSO4 .

5H2O - Blue Vitriol or Chalcanthite Nitrate Ores : (1) KNO3 - Indian Saltpetre (2) NaNO3 - Chile Saltpetre Arsenides Ores : (1) NiAs - Kupfernickel (2) NiAsS - Nickel glance

Q118

Match with . .tg .tg Ore Composition

List - I		List - II
(A)	Siderite	(I)	FeCO $_3$
(B)	Malachite	(II)	CuCO $_3$ . Cu(OH) $_2$
(C)	Sphalerite	(III)	ZnS
(D)	Calamine	(IV)	ZnCO $_3$

A A-I, B-II, C-III, D-IV

B A-III, B-IV, C-II, D-I

C A-IV, B-III, C-I, D-II

D A-I, B-II, C-IV, D-III

Correct Answer

Option A

Solution

Siderite → FeCO3 Malachite → CuCO3.

Cu(OH)2 Sphalerite → ZnS Calamine → ZnCO3 Note : ( Remember all those ores names.

Any one of those can be asked in the exam.)

Oxides Ores : (1) ZnO - Zincite (2) Fe2O3 - Haematite (3) Fe3O4 - Magnetite (FeO + Fe2O3 mixture) (4) Fe2O3 .

3H2O - Limonite (5) MnO2 - Pyrolusite (6) Cu2O - Cuprite or Ruby Copper (7) TiO2 - Rutile (8) FeCr2O4 - Chromite (FeO + Cr2O3) (9) FeTiO3 - Illmenite (FeO + TiO2) (10) Na2B4O7 .

10H2O - Borax or Tincal (11) U3O8 - Pitch Blende (12) SnO2 - Tin Stone or Cassiterite (13) Ca2B6O11 .

5H2O - Colemanite (2 Cao + 3 B2O3) (14) Al2O3 .

2H2O - Bauxite (15) Al2O3 .

H2O - Diaspore (16) Al2O3 - Corundum Sulphides Ores : (1) ZnS - Zinc Blende or Sphalerite (2) PbS - Galena (3) Ag2S - Argentite or Silver Glance (4) HgS - Cinnabar (5) Cu2S - Chalcocite or Copper glance (6) CuFeS2 - Copper pyrites or Chalco pyrites (Cu2S + Fe2S3 mixture) (7) FeS2 - Iron pyrites or Fool's Gold (8) 3Ag2S .

Sb2S2 - Pyrargyrite or ruby silver Halides Ores : (1) NaCl - Rock Salt (2) KCl - Sylvine (3) Na3AlF6 - Cryolite [3NaF + AlF6] (4) CaF2 - Fluorspar (5) KCl .

MgCl2 .

6H2O - Carnalite (6) AgCl - Horn Silver Carbonates Ores : (1) CaCO3 - Limestone (2) MgCO3 - Magnesite (3) CaCO3 .

MgCO3 - Dolomite (4) ZnCO3 - Calamine (5) PbCO3 - Cerrusite (6) FeCO3 - Siderite (7) CuCO3 .

Cu(OH)2 or Cu2CO3(OH)2 - Malachite or Basic Copper Carbonates (8) 2 CuCO3 .

Cu(OH)2 - Azurite Sulphates Ores : (1) CuSO4 .

2H2O - Gypsum (2) MgSO4 .

7H2O - Epson Salt (3) Na2SO4 .

10 H2O - Glauber's Salt (4) PbSO4 - Anglesite (5) ZnSO4 .

7H2O - White Vitriol (6) FeSO4 .

7H2O - Green Vitriol (7) CuSO4 .

5H2O - Blue Vitriol or Chalcanthite Nitrate Ores : (1) KNO3 - Indian Saltpetre (2) NaNO3 - Chile Saltpetre Arsenides Ores : (1) NiAs - Kupfernickel (2) NiAsS - Nickel glance

Q119

The pair of compounds having metals in their highest oxidation state is :

A MnO2 and CrO2Cl2

B [NiCl4]2

-

and [CoCl4]2

-

C [Fe(CN)6]3

-

and [Cu(CN)4]2

-

D [FeCl4]

-

and Co2O3

Correct Answer

Option A

Solution

.tg .tg Complex Metal Oxidation state

{[Fe{(CN)_6}]^{2 - }}

and

{[Cu{(CN)_4}]^{2 - }}

Fe and Cu +4 and +2

{[FeC{l_4}]^ - }

and

C{o_2}{O_3}

Fe and Co +3 and +3

{[NiC{l_4}]^{2 - }}

and

{[CoC{l_4}]^{2 - }}

Ni and Co +2 and +2

Mn{O_2}

and

Cr{O_2}C{l_2}

Mn and Cr +4 and +6 In order to determine which pair of compounds have metals in their highest oxidation states, we need to consider the common oxidation states of the metals involved, as well as the rules for determining oxidation states in compounds and complex ions.

Let's evaluate each option: Option A: MnO2 and CrO2Cl2 In MnO2, manganese (Mn) has an oxidation state of +4.

This is not the highest oxidation state manganese can achieve; it can go up to +7, as seen in KMnO4 (potassium permanganate).

In CrO2Cl2, chromium (Cr) has an oxidation state of +6, which is indeed its highest oxidation state.

Thus, this option contains one metal in its highest oxidation state (Cr) but not the other (Mn).

Option B: [NiCl4]2- and [CoCl4]2- For both [NiCl4]2- and [CoCl4]2-, the nickel (Ni) and cobalt (Co) are in a +2 oxidation state.

Neither of these represents the highest oxidation state for these metals.

Nickel can have a +3 state, and cobalt can go up to +4 in very rare cases.

Option C: [Fe(CN)6]3- and [Cu(CN)4]2- In [Fe(CN)6]3-, the iron (Fe) has an oxidation state of +3, which is a common high oxidation state for iron, though iron can also exist in a +2 state commonly and +6 in very rare conditions.

Therefore, +3 is considered a high oxidation state but not the absolute highest.

In [Cu(CN)4]2-, copper (Cu) has an oxidation state of +2, which is the highest stable oxidation state for copper in most of its compounds.

Option D: [FeCl4]- and Co2O3 In [FeCl4]-, iron (Fe) has an oxidation state of +3.

As mentioned, +3 is a high state for iron, but not the absolute highest oxidation state it can achieve.

In Co2O3, cobalt (Co) has an oxidation state of +3, as evidenced by the formula, where two Co atoms interact with three O atoms (each oxygen providing a -2 charge, for a total of -6, requiring each Co to be +3 to balance the charge). +3 is indeed among the highest common oxidation states for cobalt, although, as mentioned, Co can technically reach +4.

Conclusion: Based on above analysis, while none of the options perfectly fits the criteria of both elements being in their absolute highest oxidation states (especially considering the rare or less common states), Option A and Option D come closest, with chromium and cobalt being in their common high oxidation states in the provided compounds.

However, the question asks for the highest oxidation state, and strictly speaking, none of the options perfectly satisfy the condition for both elements included.

Among the choices, Option A is the closest because chromium is in its highest oxidation state of +6 in CrO2Cl2, and manganese in MnO2 is in a +4 state, which while not its absolute highest, represents a commonly encountered high oxidation state.

Given the context and conventional exams' focus on common oxidation states, Option A would be the best fit despite the slight discrepancy with the question's phrasing.

Q120

What is the correct order of the following elements with respect to their density?

A Cr < Zn < Co < Cu < Fe

B Cr < Fe < Co < Cu < Zn

C Zn < Cr < Fe < Co < Cu

D Zn < Cu < Co < Fe < Cr

Correct Answer

Option C

Solution

Generally, due to decrease in metallic radius and increase in atomic mass density increase across the period from left to right.

Metal Density

(g/c{m^3})

Zn 7.13 Cr 7.19 Fe 7.8 Co 8.7 Cu 8.9 Correct order is Cu > Co > Fe > Cr > Zn.