Test: Level - 2 Isolation - 1


30 Questions MCQ Test Chemistry Class 12 | Test: Level - 2 Isolation - 1


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This mock test of Test: Level - 2 Isolation - 1 for Class 12 helps you for every Class 12 entrance exam. This contains 30 Multiple Choice Questions for Class 12 Test: Level - 2 Isolation - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Level - 2 Isolation - 1 quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this Test: Level - 2 Isolation - 1 exercise for a better result in the exam. You can find other Test: Level - 2 Isolation - 1 extra questions, long questions & short questions for Class 12 on EduRev as well by searching above.
QUESTION: 1

Formation of metallic copper from the sulphide ore in the commercial thermo-metallurgical process essentially involves which one of the following reaction :

Solution:

Self reduction process

2Cu2O + Cu2S → 6Cu + SO2

QUESTION: 2

Ag2S + NaCN + Zn →Ag

This method of extraction of Ag by complex formation and then its displacement is called :

Solution:

The process mention is rxn is known as Mc.
Arthur forest Method :

QUESTION: 3

Calcination is the process of heating the ore :

Solution:

The correct answer is option C.
Calcination is a thermal treatment process in the absence or limited supply of air or oxygen applied to ores and other solid materials to bring about a thermal decomposition, phase transition, or removal of a volatile fraction.
 

QUESTION: 4

Which of the following does not contain Mg :

Solution:

The correct answer is option A.
Magnetite is a rock mineral and one of the main iron ores, with the chemical formula Fe3O4. It does not contain Mg.
Magnesite is a magnesium carbonate mineral with a chemical composition of MgCO3
Asbestos is CaMg3(SiO3)4.
Carnallite is an evaporite mineral, a hydrated potassium magnesium chloride with formula KMgCl3⋅6(H2O).

QUESTION: 5

Match the method of concentration of the ore in column I with the ore in column II and select the correct alternate:

Solution:

Magnete seperation → FeCr2O4
froath floatation → Ag2S
gravity separation → Al2 (SiO3)2

QUESTION: 6

Bessemerization is carried out for

(I) Fe
(II) Cu
(III) Al
(IV) silver

Solution:

Bessermerisatioin process is used for Fe and Cu

QUESTION: 7

Refining of silver is done by :

Solution:

By cupellation it is urea for the removal of Pb from Ag and Au

QUESTION: 8

Which of the following is not used for obtaining Ag

Solution:
QUESTION: 9

Blister Cu is about :

Solution:

Blister copper is 98 % pure Cu

QUESTION: 10

Which one of the following is not a method of concentration of ore?

Solution:

S melting is not a process of concn of ore.

QUESTION: 11

In which of the following isolations no reducing agent is required :

Solution:

Mercury from cinnarbar (HgS)
(Auto reductant and self reduction) (Cu2S, PbS, HgS)

QUESTION: 12

Chemical leaching is useful in the concentration of :

Solution:

leaching is used for bauxite

QUESTION: 13

The element which could be extracted by electrolytic reduction of its oxide dissolved in a high temperature melt is :

Solution:

Aluminium oxide could be extracted by electrolysis phenomenon.

QUESTION: 14

Consider the following statements :

Roasting is carried out to :

(i) convert sulphide to oxide and sulphate (ii) remove water of hydration

(iii) melt the ore (iv) remove arsenic and sulphur impurities

Of these statements :

Solution:

The correct answer is Option C.
ROASTING 
The removal of the excess sulphur contained in sulphide ores by heating in an excess of air is called roasting. The concentrated sulphide ore is heated in a reverberatory furnace, below its melting point or fusion temperature in the presence of an excess of air with or without the addition of an external substance. 
In roasting definite chemicals like oxidation, chlorination etc. take place but in calcination does not occur any major chemical changes.
 
Advantages of Roasting :
(i) Excess of sulphur is removed as volatile oxide. 
(ii) The metal sulphide is converted into metal oxide and sulphate. 
(iii) Impurities of arsenic and antimony are removed as their volatile oxides.
 

QUESTION: 15

Iron obtained from blast furance is :

Solution:

Iron obtained from blast furnace is pig iron

QUESTION: 16

Which one of the following statements is not correct :

Solution:

(A) Malachite Cu(OH)2 . CuCO3
(B) Calamine ZnCO3
(C) Cerussite PbCO3
Stellite is an ore

QUESTION: 17

Which of the following is not an ore :

Solution:

Some transition metal can form poly nuclear metal carbonyls also.

QUESTION: 18

In the extraction of nickel by Mond process, the metal is obtained by :

Solution:

Thermal decomposition

QUESTION: 19

B4C(boron carbide) is used except:

Solution:

The correct answer is Option D.
Boron carbide B4C is not used for making diborane.
It is used in the extraction of boron, as an abrasive for polishing and for making bullet proof clothing.
 

QUESTION: 20

Froath floatation process is based on:

Solution:

The correct is Option A.

Froth flotation is a process of  concentration. Froth floatation process is suitable for sulphide ores. It is based on the difference in wetting properties of the ore and gangue with water and oil. This method is used for the concentration of FeCr2O4 

QUESTION: 21

When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, because

Solution:

PbS + NaCN/KCN → No. reaction
ZnS + NaCN/KCN → [Zn(CN)4]2– + S2– + 4Na+/ 4K+

QUESTION: 22

When copper is purified by electrorefining process, noble metals like Ag and Au are found in

Solution:

Cu and Ag are found in anode mud.

QUESTION: 23

Formation of Ni(CO)4 and subsequent its decomposition into Ni and CO (recycled) makes basis of Mond's process

Ni + 4CO  Ni (CO)  Ni + 4CO

T1 and T2 are :

Solution:

Ni + 4CO  Ni (CO)  Ni + 4CO
T1 = 50ºC
T2 = 230ºC

QUESTION: 24

Match column–I (process) with column–II (electrolyte) :

Choose the correct alternate.

Solution:

Down cell → Fused (40 % NaCl + 60 % CaCl2)
Dow seawater process → fused NaCl2
Hall-heroult ⇒ fused (Al2O3 + Na3AlF6 + CaF2)
Moissan → Fused KHF2

QUESTION: 25

(I) FeCr2O4 + NaOH + air → (A) + Fe2O3

(II) (A) + (B) → Na2Cr2O7

(III) Na2Cr2O7 + X  Cr2O3

(IV) Cr2O3 + Y  Cr

Q.

Compounds (A) and (B) are :

Solution:

A → Na2CrO4
B → H2SO4

QUESTION: 26

(I) FeCr2O4 + NaOH + air → (A) + Fe2O3

(II) (A) + (B) → Na2Cr2O7

(III) Na2Cr2O7 + X  Cr2O3

(IV) Cr2O3 + Y  Cr

Q.

(X) and (Y) are :

Solution:

X → CO
Y → Al

QUESTION: 27

(I) FeCr2O4 + NaOH + air → (A) + Fe2O3

(II) (A) + (B) → Na2Cr2O7

(III) Na2Cr2O7 + X  Cr2O3

(IV) Cr2O3 + Y  Cr

Q.

Na2CrO4 and Fe2O3 are separated by :

Solution:
QUESTION: 28

(I) FeCr2O4 + NaOH + air → (A) + Fe2O3

(II) (A) + (B) → Na2Cr2O7

(III) Na2Cr2O7 + X  Cr2O3

(IV) Cr2O3 + Y  Cr

Q.

High temperature (> 1000ºC) electrolytic reduction is necessary for isolating :

Solution:

The correct answer is option A.
Chromite ore is heated with sodium hydroxide in air to obtain sodium chromate. It is then heated with carbon to obtain chromium trioxide. It is then heated with aluminum to form chromium. This is reduction of chromium trioxide to chromium.

QUESTION: 29

In froth-floatation process, palm oil functions as :

Solution:

Palm oil function as frother. It decreases the surface tension of the total solution, by which the formation of froth becomes easier.

QUESTION: 30

Collector are the substances which help in attachement of an ore particle to air bubble in froth. A popular collector used industrially is :

Solution:

The correct answer is option A.
Sodium ethyl xanthate is used as a collector in the froth floatation process.
Froth floatation process used for the concentration of sulphide ore uses sodium ethyl xanthate, C2H5OCS2Na as collector.
Other examples of collector include ethyl xanthate and potassium ethyl xanthate. They attach themselves to the grains of minerals by polar groups so that minerals become water repellent and pass on into the froth.