Test: Metallurgy Process Of Concentration Of Ores


25 Questions MCQ Test Chemistry Class 12 | Test: Metallurgy Process Of Concentration Of Ores


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This mock test of Test: Metallurgy Process Of Concentration Of Ores for Class 12 helps you for every Class 12 entrance exam. This contains 25 Multiple Choice Questions for Class 12 Test: Metallurgy Process Of Concentration Of Ores (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Metallurgy Process Of Concentration Of Ores quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this Test: Metallurgy Process Of Concentration Of Ores exercise for a better result in the exam. You can find other Test: Metallurgy Process Of Concentration Of Ores extra questions, long questions & short questions for Class 12 on EduRev as well by searching above.
QUESTION: 1

Only One Option Correct Type

This section contains 10 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONLY ONE is correct

Q.

Flux is often added to remove impurities from an iron ore in a blast furnace. In the reaction slag and flux are

Solution:

CaCO3 → CaO + CO2
CaO + SiO2 → CaSiO3

QUESTION: 2

Froth flotation process is based on

Solution:

This method is based upon the fact that the surface of sulphide over is preferentially wetted by oils while that of gangue is preferentially wetted by water.

QUESTION: 3

Which one of the following ores is concentrated by chemical leaching method?

Solution:

In this process the finely divided powdered argentite or the native silver or gold is treated with a dilute solution (0.5%) of sodium or potassium cyanide while a current of air is continuously passed. As a result silver pass into solution forming their respective soluble complex cyanides while the impurities remain unaffected which are filtered off.

QUESTION: 4

Which of the ore dressing process requires finest size of ore?

Solution:

The ore is crushed into a fine powder and mixed with water to form suspension.

QUESTION: 5

Wolframite(FeWO4) impurities present in cassiterite (SnO2) can be separated by the process of

Solution:

Electromagnetic separation method of concentration is employed when either the ore or the impurities associated with it are magnetic in nature. Tinstone or cassiterite (SnO2) an ore of tin being non-magnetic can be separated from magnetic impurities (FeWO4).

QUESTION: 6

In the metallurgical process, the flux used for removing basic impurities is

Solution:

 
 

 

QUESTION: 7

Gravity method of ore concentration depends on

Solution:

The mineral particle becom es wet by oils while the gangue particles by water. A rotating paddle agitates the mixtures and draws air in it. As a result froth is formed which carrier the mineral particles. The froth is light and is skimmed of. If is then dried for recovery of the ore particles.

QUESTION: 8

Sulphide ores of metals are usually concentrated by froth floatation process.Which one of the following sulphide ores offers an exception and  is concentrated by leaching?

Solution:

Leaching This process consists in treating the powdered ore with a suitable reagent (such as acids, bases or other chemicals) which can selectively dissolves the ore but not the impuritier. It is used to extract silver metals.

QUESTION: 9

The slag formed in the extraction of iron and copper respectively are 

Solution:


QUESTION: 10

In the froth floatation process for benefaction of the ores, the ore particles float because

Solution:

The ore particles preferentially wetted by the oil become lighter and thus rise to the surface along with the froth while the gangue particle wetted by wated become heavier and thus settle down at the bottom.

*Multiple options can be correct
QUESTION: 11

One or More than One Options Correct Type

This section contains 5 multiple type questions. Each question has 4 choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.?

Q.

The ore that is concentrated by froth floatation process is

Solution:

Cinnabar, Galena , zinc blende are concetrated by froth floatation method.

*Multiple options can be correct
QUESTION: 12

In froth floatation process the particles of the ore come on the froth because

Solution:

They are light and water repellent.

*Multiple options can be correct
QUESTION: 13

Purification of bauxite is called

Solution:

Hoope's method is used to obtain aluminium of very high purity. The metal obtained in the Hall-Heroult process is about 99% pure and for most purposes it is taken as pure metal. However further purification of aluminium can be carried out by the Hoope’s process. This is an electrolytic process.

*Multiple options can be correct
QUESTION: 14

The common impurities found in bauxite are

Solution:

The common impurities present in bauxite are Fe2O3 and SiO2.

*Multiple options can be correct
QUESTION: 15

Which of the following chemicals are involved in froth floatation process?

Solution:

Flux is not involved in froth floatation process.

QUESTION: 16

Comprehension Type

This section contains a passage describing theory, experiments, data, etc. Two questions related to the paragraph have been given. Each question has only one correct answer out of the given 4 options (a), (b), (c) and (d).

Passage

Most of the ores available in nature contain large amount of impurities i.e. gangue. The pretreatment of ores, based on physical properties and without bringing out any major chemical change in the ore is called ore dressing or ore concentration.

Q. Which of the following is related to ore concentration?

Solution:

The process by which lighter earthly particles are free from the heavier ore particles by washing with water is called levigation.

QUESTION: 17

Most of the ores available in nature contain large amount of impurities i.e. gangue. The pretreatment of ores, based on physical properties and without bringing out any major chemical change in the ore is called ore dressing or ore concentration.

Q. 

In the purification of bauxite by leaching, the chemicals employed in Baeyer’s and Hall’s process respectively are

Solution:

In the Baeyer process Al2O3 is obtained from bauxite ore by treating the powered ore with a strong solution of NaOH when alumina (Al2O3) dissolves forming sodium mefa-aluminate leaving behind impurities.

QUESTION: 18

Matching List Type

Choices for the correct combination of elements from Column I and Column II are given as options (a), (b), (c) and (d), out of which one is correct.

Q. 

Match the Column I with Column II and mark the correct option from the codes given below.

Solution:

(i) → (r), (ii) → (p), (iii) → (q), (iv) → (s)

QUESTION: 19

Match the Column I with Column II and mark the correct option from the codes given below.

Solution:

(i) → (q), (ii) → (r,t), (iii) → (p), (iv)→ (s)

*Answer can only contain numeric values
QUESTION: 20

One Integer Value Correct Type

This section contains 5 questions, when worked out will result in an integer value from 0 to 9 (both inclusive).

Q.

The number of ores concentrated by froth floatation process among cassiterite, galena, zinc blende, chromite, haematite, copper iron pyrites


Solution:

Galena, zinc blende and copper iron pyrites are concentrated by froth floatation method.

*Answer can only contain numeric values
QUESTION: 21

The number of ores concentrated by leaching or wet process among calamine, tinstone, bauxite, argentite, horn silver, galena, cinnabar, native gold


Solution:

Bauxite, horn silver, native gold, tinstone.

*Answer can only contain numeric values
QUESTION: 22

In the leaching of Ag2S with NaCN the equation is

Ag2S + 4NaCN → 2Na[Ag(CN)2] + Na2S. In this change in oxidation state of silver.


Solution:

In this reaction oxidation state of silver is zero.

*Answer can only contain numeric values
QUESTION: 23

Number of ores concentrated by Levigation (hydraulic washing) among pitche blende, tinstone, chromite, galena, copper pyrites, argentite.


Solution:

Pitche blende, tinstone, chromite are purified by levigation.

*Answer can only contain numeric values
QUESTION: 24

The number of magnetic substances among : tinstone, wolframite, chromite, magnetite, pyrolusite, rutile, magnesite, sphalerite


Solution:

Wolframite, chromite, magnetite, rutile (contain iron impurities).

QUESTION: 25

Statement Type

Direction : This section is based on Statements I and Statements II. Select the correct answer from the codes given below.

Q. 

Statement I : Cresol and aniline are froth stabilisers.

Statement II : Collectors enhance the non-wettability of the ore particles.

Solution:

Because cresol and aniline are froth stabilisers, but only ethyl xanthate, pine oil which enhance non-wettability of ore particles.

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