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#### Metallurgy one marks

12th Standard EM

Reg.No. :
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Chemistry

Time : 02:00:00 Hrs
Total Marks : 100
Part-A
73 x 1 = 73
1. Bauxite has the composition

(a)

Al2O3

(b)

Al2O3nH2O

(c)

Fe2O3.2H2O

(d)

None of these

2. Roasting of sulphide ore gives the gas (A).(A) is a colourless gas. Aqueous solution of (A) is acidic. The gas (A) is

(a)

CO2

(b)

So3

(c)

SO2

(d)

H2S

3. Which one of the following reaction represents calcinations?

(a)

$2Zn+{ O }_{ 2 }\rightarrow 2ZnO$

(b)

$2ZnS+3O_{ 2 }\rightarrow 2ZnS+3O_{ 2 }\rightarrow 2ZnO_{ 2 }\rightarrow 2ZnO+2SO_{ 2 }$

(c)

$MgCO_{ 3 }\rightarrow MgO+CO_{ 2 }$

(d)

Both (a) and (c)

4. The metal oxide which cannot be reduced to metal by carbon is

(a)

PbO

(b)

AL2O3

(c)

ZnO

(d)

Feo

5. Which of the metal is extracted by Hall-Heroult process?

(a)

Al

(b)

Ni

(c)

Cu

(d)

Zn

6. Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?

(a)

$\Delta { G }_{ f }^{ 0 }$ of sulphide is greater than those for CS2 and H2S

(b)

$\Delta { G }_{ r }^{ 0 }$ is negative for roasting of sulphide ore to oxide

(c)

Roasting of the sulphide to its oxide is thermodynamically feasible

(d)

Carbon and hydrogen are suitable reducing agents for metal sulphides

7. Match items in column - I with the items of column – II and assign the correct code.

 Column-I Column-II A. Cyanide process (i) Ultrapure Ge B Froth floatation process (ii) Dressing of ZnS C Electrolytic reduction (iii) Extraction of Al D Zone refining (iv) Extraction of Au (v) Purification of Ni
(a)
 A B C D
(b)
 A B C D (i) (ii) (iii) (iv)
(c)
 A B C D (iii) (iv) (v) (i)
(d)
 A B C D (ii) (iii) (i) (v)
8. Wolframite ore is separated from tinstone by the process of

(a)

Smelting

(b)

Calcination

(c)

Roasting

(d)

Electromagnetic separation

9. Which one of the following is not feasible

(a)

$Zn(s)+C{ u }^{ 2+ }\left( aq \right) \rightarrow Cu\left( s \right) +{ Zn }^{ 2+ }(aq)$

(b)

$Cu(s)+Z{ n }^{ 2+ }(aq)\longrightarrow Zn(s)+{ Cu }^{ 2+ }(aq)$

(c)

$Cu(s)+2Ag^{ + }(aq)\longrightarrow Ag(s)+{ Cu }^{ 2+ }(aq)$

(d)

$Fe(s)+{ Cu }^{ 2+ }(aq)\longrightarrow Cu(s)+{ Fe }^{ 2+ }(aq)$

10. Electrochemical process is used to extract

(a)

Iron

(b)

(c)

Sodium

(d)

silver

11. Flux is a substance which is used to convert

(a)

Mineral into silicate

(b)

Infusible impurities to soluble impurities

(c)

Soluble impurities to infusible impurities

(d)

All of these

12. Which one of the following ores is best concentrated by froth – floatation method?

(a)

Magnetite

(b)

Hematite

(c)

Galena

(d)

Cassiterite

13. In the extraction of aluminium from alumina by electrolysis, cryolite is added to

(a)

Lower the melting point of alumina

(b)

Remove impurities from alumina

(c)

Decrease the electrical conductivity

(d)

Increase the rate of reduction

14. Zinc is obtained from ZnO by

(a)

Carbon reduction

(b)

Reduction using silver

(c)

Electrochemical process

(d)

Acid leaching

15. Cupellation is a process used for the refining of

(a)

Silver

(b)

(c)

Copper

(d)

iron

16. Extraction of gold and silver involves leaching with cyanide ion. silver is later recovered by (NEET-2017)

(a)

Distillation

(b)

Zone refining

(c)

Displacement with zinc

(d)

liquation

17. Considering Ellingham diagram, which of the following metals can be used to reduce alumina? (NEET-2018)

(a)

Fe

(b)

Cu

(c)

Mg

(d)

Zn

18. The following set of reactions are used in refining Zirconium
$(impure)+2I_{ 2 }\overset { 523k }{ \longrightarrow } ZrI_{ 4 }$
${ ZrI }_{ 4 }\overset { 1800K }{ \longrightarrow } Zr(pure)+{ 2I }_{ 2 }$
This method is known as

(a)

Liquation

(b)

van Arkel process

(c)

Zone refining

(d)

Mond’s process

19. Which of the following is used for concentrating ore in metallurgy?

(a)

Leaching

(b)

Roasting

(c)

Froth floatation

(d)

Both (a) and (c)

20. The incorrect statement among the following is

(a)

Nickel is refined by Mond’s process

(b)

Titanium is refined by Van Arkel’s process

(c)

Zinc blende is concentrated by froth floatation

(d)

In the metallurgy of gold, the metal is leached with dilute sodium chloride solution

21. In the electrolytic refining of copper, which one of the following is used as anode?

(a)

Pure copper

(b)

Impure copper

(c)

Carbon rod

(d)

Platinum electrode

22. Which of the following plot gives Ellingham diagram

(a)

$\Delta SVsT$

(b)

$\Delta { G }^{ 0 }VsT$

(c)

$\Delta { G }^{ 0 }Vs\cfrac { 1 }{ T }$

(d)

$\Delta { G }^{ 0 }Vs{ T }^{ 2 }$

23. In the Ellingham diagram, for the formation of carbon monoxide

(a)

$\left( \cfrac { \Delta { S }^{ 0 } }{ \Delta T } \right)$

(b)

$\left( \cfrac { \Delta { G }^{ 0 } }{ \Delta T } \right)$ is positive

(c)

$\left( \cfrac { \Delta { G }^{ 0 } }{ \Delta T } \right)$ is negative

(d)

initially $\left( \cfrac { \Delta T }{ \Delta { G }^{ 0 } } \right)$ is positive, after 700oC,$\left( \cfrac { \Delta { G }^{ 0 } }{ \Delta T } \right)$ is negative

24. Which of the following reduction is not thermodynamically feasible?

(a)

${ Cr }_{ 2 }{ O }_{ 3 }+2Al\longrightarrow { Al }_{ 2 }{ O }_{ 3 }+2Cr$

(b)

${ Al }_{ 2 }{ O }_{ 3 }+2Cr\longrightarrow { Cr }_{ 2 }{ O }_{ 3 }+2Sl$

(c)

$3Ti{ O }_{ 2 }+4Al\longrightarrow 2A{ l }_{ 2 }{ O }_{ 3 }+3Ti$

(d)

none of these

25. Which of the following is not true with respect to Ellingham diagram?

(a)

Free energy changes follow a straight line. Deviation occurs when there is a phase change.

(b)

The graph for the formation of CO2 is a straight line almost parallel to free energy axis.

(c)

Negative slope of CO shows that it becomes more stable with increase in temperature

(d)

Positive slope of metal oxides shows that their stabilities decrease with increase in temperature

26. Which metal is used for extraction of Au and Ag and also for galvanisation of iron objects?

(a)

Mg

(b)

Zn

(c)

Cr

(d)

Co

27. Which of the following is not a mineral of aluminium?

(a)

Bauxite

(b)

Cryolite

(c)

China clay

(d)

Malachite

28. Which of the following is commonly used to produce foam in froth floatation process?

(a)

Pine oil

(b)

Cresol

(c)

NaCN

(d)

Xanthate

29. Among the following, one does not belong to calcination, Pick the odd one out.

(a)

${ PBCO }_{ 3 }\overset { \Delta }{ \longrightarrow } PBO+{ CO }_{ 2 }\uparrow$

(b)

${ CaCo }_{ 3 }\overset { \Delta }{ \longrightarrow } Cao+{ CO }_{ 2 }\uparrow$

(c)

$PbS{ O }_{ 3 }\overset { \Delta }{ \rightarrow } PbO+{ 2SO }_{ 2 }\uparrow$

(d)

${ ZnCO }_{ 3 }\overset { \Delta }{ \rightarrow } ZnO+{ CO }_{ 2 }\uparrow$

30. Which of the following is incorrect with respect to metallurgy of iron in the blast furnace?

(a)

Zone of combustion : $C+{ O }_{ 2 }\rightarrow { CO }_{ 2 }$

(b)

Zone of heat absorption : ${ CO }_{ 2 }\rightarrow C+{ O }_{ 2 }$

(c)

Zone of slag formation : $CaO+{ SiO }_{ 2 }\rightarrow CaSiO_{ 3 }$

(d)

Zone of reduction : ${ Fe }_{ 2 }{ O }_{ 3 }3C\rightarrow 3CO+2Fe$

31. Name the process by which elements such as germanium, silicon and galium are refined.

(a)

Vapour phase method

(b)

Electrolytic refining

(c)

Zone refining

(d)

Van-Arkel method

32. Which of the following will give respective metal by self reduction?

(a)

Galena (Pbs)

(b)

HgS

(c)

ZnS

(d)

Both (a) & (b)

33. In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with

(a)

Iron sulphide (FeS)

(b)

Carbon monoxide (CO)

(c)

Copper (I) sulphide (Cu2S)

(d)

Sulphur dioxide (S02)

34. Which among the following reaction represents the formation of slag?

(a)

$Ca{ O }_{ (s) }+{ SiO }_{ 2(s) }\longrightarrow { CaSiO }_{ 3(s) }$

(b)

${ 2C }_{ (s) }+{ O }_{ 2(g) }\longrightarrow { 2CO }_{ (g) }$

(c)

${ Fe }_{ 2 }{ O }_{ 3 }+{ 3CO }_{ (g) }\longrightarrow 2{ Fe }_{ (l) }+{ 3CO }_{ 2(g) }$

(d)

${ CaCO }_{ 3(g) }\longrightarrow { CaO }_{ (s) }+{ CO }_{ 2(g) }$

35. Which one of the following element is present as a~ impurity in pig iron?

(a)

Phosphorus

(b)

Manganese

(c)

Carbon

(d)

Silicon

36. Which of the following mineral contains calcium as well as magnesium?

(a)

Zinc bien de

(b)

Aragonite

(c)

Dolomite

(d)

Carnalite

37. In the froth-floatation process the collectors such as pine oil and xanthates, etc enhance.

(a)

Non-wettability of the mineral particles in froth.

(b)

Non-wettability of the mineral particles in water

(c)

Non-wettability of the gangue particles in froth

(d)

Non-wettability of the gangue particles in water

38. Concentration of copper glance is done by

(a)

leaching

(b)

magnetic separation

(c)

froth flotation

(d)

hydraulic washing

39. Identify the decreasing order of carbon content in different forms of iron

(a)

Wrought iron> Pig iron> castiron

(b)

Castiron > Pig iron> Wrought iron

(c)

Pig iron> Cast iron> Wrought iron

(d)

Cast iron> Wrought iron> Pig iron

40. Sodium. magnesium and aluminum can be obtained from their ore by

(a)

electro metallurgy

(b)

pyro metallurgy

(c)

hydro metallurgy

(d)

smelting

41. The blistered appearance of Cu obtained from the reverberatory furance is due to evolution of

(a)

CO2 gas

(b)

S02 gas

(c)

NO2

(d)

Due to evaporation of volatile materials

42. Identify the halide ore among the following

(a)

Epsom Salt

(b)

Pyrolusite

(c)

Anglesite

(d)

Rock Salt

43. Identify the metal that occurs in free state

(a)

Al

(b)

Au

(c)

Mg

(d)

Ca

44. $2PbS+{ 3O }_{ 2 }\longrightarrow 2pbO+{ 2SO }_{ 2 }$ Name the process

(a)

Roasting

(b)

Calcination

(c)

Smelting

(d)

Leaching

45. The process of heating of copper pyrites to remove sulphur is called

(a)

froth flotation

(b)

roasting

(c)

calcination

(d)

smelling

46. $\Delta { G }^{ o }$ vs T plot in the Ellingham's diagram slopes downward the reaction.

(a)

$Mg+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow MgO$

(b)

$C+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow CO$

(c)

$2Ag+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow { Ag }_{ 2 }O$

(d)

$2Ag+\cfrac { 1 }{ 2 } { O }_{ 2 }\longrightarrow { Ag }_{ 2 }O$

47. Pick out the alloy that contains a non-metal as a constituent in it

(a)

Brass

(b)

Bronze

(c)

Steel

(d)

Invar

48. Ignition mixture used in aluminothermite process is

(a)

Cr + AI2O3

(b)

Mg + BaO2

(c)

AI + Cr2O3

(d)

Ba+MgO

49. Malachite has______ composition.

(a)

2CuCO3.Cu(OH)2

(b)

2CuCO3.Cu(OH)2

(c)

Cu2O

(d)

Cu2S

50. Zinc blende is_________

(a)

ZnS

(b)

PbS

(c)

Ag2S

(d)

Cu2S

51. In acid leaching process. the insoluble sulphide is converted into soluble sulphate and elemental_________

(a)

carbon

(b)

(c)

sulphur

(d)

zinc

52. Sulphide ore is converted to oxide form by using the process_________

(a)

Calcination

(b)

Roasting

(c)

Smelting

(d)

Leavhing

53. Magnetic separation it is based on the difference in the_________ of the ore and the impurities.

(a)

magnetic properties

(b)

chemical properties

(c)

physical properties

(d)

melting point

54. Zinc is extracted from Zinc blende by_________

(a)

Carbon reduction process

(b)

Nitrogen reduction process

(c)

Oxygen reduction process

(d)

All of these

55. $ZnS+{ 3O }_{ 2 }\overset { \Delta }{ \longrightarrow } 2ZnO+{ 2SO }_{ 2 }\uparrow$ .The above equation is an example for________.

(a)

calcination

(b)

reduction

(c)

roasting

(d)

leaching

56. Gibb's free energy is given by_______

(a)

$\Delta { G }^{ 0 }=-nF{ E }^{ 0 }$

(b)

$\Delta { G }^{ o }=nF$

(c)

$\Delta { G }^{ o }=nF{ E }^{ o }$

(d)

$\Delta { E }^{ o }=-nF{ G }^{ 0 }$

57. Na[Ag(CN)2] is _________.

(a)

Sodium aurocyanide

(b)

Sodium meta aluminate

(c)

Aluminosilicate

(d)

Sodium dicyano argentate

58. ${ Zn }_{ (s) }+2\left[ Au(CN)_{ 2 } \right] ^{ - }_{ (aq) }\longrightarrow \left[ Zn(CN)_{ 4 } \right] ^{ 2- }_{ (aq) }+2Au{ { u }_{ (s) } }$ In the above equation) the oxidation state of metallic;gold is_______

(a)

1

(b)

0

(c)

+2

(d)

-2

59. Semiconductors are purified by_______method.

(a)

Zone refining

(b)

Electrolytic refining

(c)

Mond's process

(d)

Beisemerisation

60. Magnesite is_________

(a)

Magnesium oxide

(b)

Magnesium carbonate

(c)

Magnesium sulphate

(d)

Magnesium chloride

61. The following set of reaction is used for refming titanium. This method is known as___________
${ Ti }_{ (g) }+{ 2I }_{ 2(s) }\longrightarrow { TiI }_{ 4 }\left( vapour \right)$
${ Til }_{ 4 }(va[pour)\longrightarrow Ti_{ (g) }+{ 2I }_{ 2(s) }$

(a)

Hall Herold process

(b)

Mond process

(c)

Van-Arkel process

(d)

Alumino thermic process

62. In the metallurgy of iron) limestone is added to coke. Which acts as a_______

(a)

Reducing agent

(b)

Oxidising agent

(c)

Slag

(d)

Flux

63. A mixture containing sulphides of copper and iron is called______

(a)

mineral

(b)

ore

(c)

matte

(d)

matrix

64. Cinnabar is the sulphide ore of_________metal.

(a)

Zn

(b)

Pb

(c)

Hg

(d)

Ag

65. The percentage of carbon in high carbon steel is_________

(a)

0.5 - 1%

(b)

0.15 - 1.5%

(c)

0.15 - 1.5%

(d)

0.15 - 0.3%

66. Froth floatation process is suitable for concentrating ______ores.

(a)

oxide

(b)

carbonate

(c)

sulphide

(d)

halide

67. Steelis an alloy of___________

(a)

iron and carbon

(b)

iron and calcium

(c)

copper and carbon

(d)

copper and iron

68. Metal oxide is converted into metal by the:_______ process.

(a)

Calcination

(b)

roasting

(c)

smelting

(d)

beesemerisation

69. Sodium cyanide solution is used to extract _________from its ores

(a)

copper

(b)

silver

(c)

gold

(d)

both (b) and (c)

70. In the thermite proces__________is used as a reducing agent

(a)

AI

(b)

CO

(c)

C

(d)

CO2

71. Galena is_________

(a)

PbS

(b)

ZnS

(c)

Ag2S

(d)

FeS2

72. $HgS_{ (s) }+{ O }_{ 2(g) }\longrightarrow { Hg }_{ (l) }+{ SO }_{ 2 }\uparrow$ The above reaction is an example of _________reduction.

(a)

metal

(b)

hydrogen

(c)

carbon

(d)

auto

73. In Hall-Herold process___________act as an, anode.

(a)

Carbon blocks

(b)

hydrogen

(c)

copper rods

(d)

Zinc rods

74. 20 x 1 = 20
75. Copper pyrite

76. (1)

Zn

77. Malachite

78. (2)

Calamine

79. Azurite

80. (3)

Fe

81. Cuprite

82. (4)

Bauxite

83. Calamine

84. (5)

2CuCO3.Cu(OH)2

85. Azurite

86. (6)

Copper pyrite

87. Limonite

88. (7)

Zinc Blende

89. Cerrusite

90. (8)

Angelsite

91. Gravity separation

92. (9)

Tin

93. Froth floatation

94. (10)

Cu2O

95. Chemical method

96. (11)

Tinstone

97. Electro magnetic separation

98. (12)

Cu

99. Oxide ore

100. (13)

Diaspore

101. Sulphide ore

102. (14)

CuFeS2

103. Sulphate ore

104. (15)

Nickel

105. Carbonate ore

106. (16)

Silicon

107. Liquation

108. (17)

Copper

109. Mond's process

110. (18)

Hematite

111. Zone refining

112. (19)

Pb

113. Electrolytic refining

114. (20)

CuCO3CU(OH)2

7 x 1 = 7
115. I.All ores are minerals
II. All minerals are not ores.
III.Aluminium can be extracted from bauxite.
IV.Aluminium can be extracted from china clay
a) Only I
b) Only II
c) III & IV
d) I, II & III

()

I,II,III

116. I. Copper is the first metal used by the human
II. Aluminuim is used in galvanising metals
III. Aluminium is a good conductor of electricity
IV.Magnets can be made from iron.
a) Only I
b) Only II
c) I, III & IV
d) III & IV

()

I, III & IV

117. I.Ellingham diagram helps to select a suitable reducing agent
II.Magnesite is calcinated to obtain magnesia.
III.Calcination is a process of cooling substances.
IV.Sulphur dioxide is harmful to the environment.
a) I, II & IV
b) Only II
c) Only I
d) III & IV

()

I, II & IV

118. I.Froth flotation is used to concentrate sulphide ores.
II. Magnetic separation is applicable for ferromagnetic ores.
III. Roasting method used to sulphide ores to oxides
IV.Magnetic separation is used to concentrate heavy oxide ores.
a) III & IV
b) Only II
c) Only I
d) I, II & III

()

I, II & III

119. I.Ores are associated with non-metallic impurities
II. Ores are associated with rockymaterials
III. Removal of impurities is known as concentration of ore.
IV. Ellingham diagram shows the stability of different metal oxides.
a) I, II, III & IV b
b) Only II
c) Only I
d) III & IV

()

I, II, III & IV

120. Identify the correct statement(s) with respect to the following reaction.
$2Na\left[ Al\left( OH \right) _{ 1 } \right] _{ (aq) }+{ CO }_{ 2(g) }\longrightarrow { Al }_{ 2 }{ O }_{ 3 }.x{ H }_{ 2 }{ O }_{ (g) }+{ 2NaHCO }_{ 3(aq) }$
(i) CO2 is acting as a reducing agent.
(ii) The solution is neutralised by passing CO2 gas to form hydrates Al2O3 precipitate.
(iii) Insoluble sulphate is converted into soluble sulphate.
(iv) The precipitate is filtered off and heated around 1670 K to get pure Alumina.
(a) only (ii)
(b) only (iv)
(c) both (ii) & (iv)
(d) both (i) and (iii)

()

both (ii) (iv)

121. Identify the correct statement with respect to the following reaction
${ Zn }_{ (g) }+2\left[ Au\left( CN \right) _{ 2 } \right] _{ (aq) }^{ - }\longrightarrow \left[ Zn(CN)_{ 4 } \right] _{ 2(aq) }^{ - }+{ 2Au }_{ (s) }$
a) The above reaction takes place in extraction of zinc.
b) Gold is reduced to its elemental state
c) The process is called ammonia leaching.
d) The above reaction is an example of cyanide leaching.
a) III & IV
c) Only I
b) II &IV
d) I, II, III & IV

()

II &IV