Class 12 Exam > Class 12 Questions > When ZnS and PbS minerals are present togethe...
Start Learning for Free
When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, because
- a)Pb(CN)2 is precipitated while no effect on ZnS
- b)ZnS forms soluble complex Na2[Zn(CN)4]
- c)bS forms soluble complex Na2[Pb(CN)4]
- d)They cannot be separated by adding NaCN
Correct answer is option 'B'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
When ZnS and PbS minerals are present together, then NaCN is added to ...
PbS + NaCN/KCN → No. reaction
ZnS + NaCN/KCN → [Zn(CN)4]2– + S2– + 4Na+/ 4K+
ZnS + NaCN/KCN → [Zn(CN)4]2– + S2– + 4Na+/ 4K+
Most Upvoted Answer
When ZnS and PbS minerals are present together, then NaCN is added to ...
Answer:
Introduction
The froth flotation process is a commonly used method for the separation of minerals based on their surface properties. In this process, different minerals are selectively attached to air bubbles and are carried to the surface of a flotation cell, while other minerals remain in the bulk solution. The addition of specific reagents helps in the selective attachment of minerals to the air bubbles.
ZnS and PbS Minerals
ZnS and PbS are two different minerals that may be present together in a mixture. In order to separate these minerals, a depressant is added to selectively suppress the floatability of one mineral while allowing the other to be floated.
NaCN as a Depressant
In the given scenario, NaCN is added as a depressant to selectively depress the floatability of ZnS while allowing PbS to be floated. This is because NaCN reacts differently with ZnS and PbS, resulting in the formation of different complexes.
Formation of Complexes
When NaCN is added to the mixture of ZnS and PbS, it reacts with ZnS to form a soluble complex Na2[Zn(CN)4]. This complex is not readily adsorbed on the air bubbles and, therefore, ZnS remains in the bulk solution and does not float.
On the other hand, PbS does not react significantly with NaCN under the given conditions. Therefore, PbS does not form any complex and remains unaffected by the addition of NaCN. As a result, PbS can still be selectively floated while ZnS is depressed.
Precipitation of Pb(CN)2
The incorrect option (a) states that Pb(CN)2 is precipitated when NaCN is added. This is not true because Pb(CN)2 is not formed as a precipitate in the presence of NaCN. Instead, PbS remains in the bulk solution and can be selectively floated after the addition of NaCN.
Conclusion
In conclusion, when ZnS and PbS minerals are present together, NaCN is added as a depressant to selectively depress the floatability of ZnS. This is because NaCN forms a soluble complex Na2[Zn(CN)4] with ZnS, preventing its attachment to air bubbles. PbS, on the other hand, remains unaffected by NaCN and can still be floated.
Introduction
The froth flotation process is a commonly used method for the separation of minerals based on their surface properties. In this process, different minerals are selectively attached to air bubbles and are carried to the surface of a flotation cell, while other minerals remain in the bulk solution. The addition of specific reagents helps in the selective attachment of minerals to the air bubbles.
ZnS and PbS Minerals
ZnS and PbS are two different minerals that may be present together in a mixture. In order to separate these minerals, a depressant is added to selectively suppress the floatability of one mineral while allowing the other to be floated.
NaCN as a Depressant
In the given scenario, NaCN is added as a depressant to selectively depress the floatability of ZnS while allowing PbS to be floated. This is because NaCN reacts differently with ZnS and PbS, resulting in the formation of different complexes.
Formation of Complexes
When NaCN is added to the mixture of ZnS and PbS, it reacts with ZnS to form a soluble complex Na2[Zn(CN)4]. This complex is not readily adsorbed on the air bubbles and, therefore, ZnS remains in the bulk solution and does not float.
On the other hand, PbS does not react significantly with NaCN under the given conditions. Therefore, PbS does not form any complex and remains unaffected by the addition of NaCN. As a result, PbS can still be selectively floated while ZnS is depressed.
Precipitation of Pb(CN)2
The incorrect option (a) states that Pb(CN)2 is precipitated when NaCN is added. This is not true because Pb(CN)2 is not formed as a precipitate in the presence of NaCN. Instead, PbS remains in the bulk solution and can be selectively floated after the addition of NaCN.
Conclusion
In conclusion, when ZnS and PbS minerals are present together, NaCN is added as a depressant to selectively depress the floatability of ZnS. This is because NaCN forms a soluble complex Na2[Zn(CN)4] with ZnS, preventing its attachment to air bubbles. PbS, on the other hand, remains unaffected by NaCN and can still be floated.
Free Test
FREE
| Start Free Test |
Community Answer
When ZnS and PbS minerals are present together, then NaCN is added to ...
When impurities such as zns is present in Pbs ,NaCN is added to depress the flotation property
|
Explore Courses for Class 12 exam
|
|
Similar Class 12 Doubts
When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer?
Question Description
When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer?.
When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer?.
Solutions for When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 12.
Download more important topics, notes, lectures and mock test series for Class 12 Exam by signing up for free.
Here you can find the meaning of When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice When ZnS and PbS minerals are present together, then NaCN is added to separate them in the froth floatation process as a depressant, becausea)Pb(CN)2is precipitated while no effect on ZnSb)ZnS forms soluble complex Na2[Zn(CN)4]c)bS forms soluble complex Na2[Pb(CN)4]d)They cannot be separated by adding NaCNCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Class 12 tests.
|
|
Explore Courses for Class 12 exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup