CBSE Class 12 Chemistry Processes Of Isolation Of Elements Notes Set C

CBSE Class 12 Chemistry notes and questions for Processes of Isolation of Elements Part C. Learning the important concepts is very important for every student to get better marks in examinations. The concepts should be clear which will help in faster learning. The attached concepts made as per NCERT and CBSE pattern will help the student to understand the chapter and score better marks in the examinations. 

GENERAL PRINCIPLES AND PROCESSES OF

ISOLATION OF ELEMENTS

VSA QUESTIONS (1 - MARK QUESTIONS)

1. Name three metals which occur in native state in nature.

[Ans. : Au, Ag and Pt]

2. What are collectors in froth flotation process? Give one example.

[Ex. : Pine oil]

*3. Give the names and formulae of three ores which are concentrated by froth floatation process.

[Ans. : Galena (PbS), zinc blend (zns) cinnabar (HgS)]

4. Among Fe, Cu, Al and Pb, which metal (s) can not be obtained by smelting.

[Ans. : Al]

5. What is the thermodynamic criteria for the feasibility of a reaction?

[Ans. : G should be –ve or log K = + ve]

8. Why can’t aluminium be reduced by carbon?

[Hint : Al is stronger reducing agent than carbon]

9. Name the most important form of iron. Mention its one use.

[Ans. : Cast iron is used for making gutter pipes, castings, railway sleepers,

toys etc.]

10. Name the impurities present in bauxite ore.

[Ans. : SiO2, Fe2O3 and TiO2]

11. What is the composition of copper matte?

[Hint : Cu2S and FeS]

12. Which from of copper is called blister copper?

13. What are froth stabilizers? Give two examples.

[Ex. : Cresol and aniline].

14. A sample of galena is contaminated with zinc blend. Name one chemical which can be used to concentrate galena selectively by froth floatation method. [Ans. : NaCN]

15. What are the constituents of German silver?

[Ans. : Cu = 25-30%, Zn = 25-30%, Ni = 40-50%]

16. Why is froth floatation process selected for concentration of the sulphide ore?

[Ans. : Sulphide ore particles are wetted by oil (Pine oil) and gangue particles by water]

17. Write the reaction involved in the extraction of copper from low grade ores.

[Ans. : First step is leaching of ore with acid or bacteria then

Cu2+ (aq) + H2 (g) Cu(s) + 2H+ (g)]

18. Although aluminium is above hydrogen in the electrochemical series, it is stable in air and water. Why?

19. Which method of purification is represented by the following reaction

class_12_chemistry_concept_54

20. Zinc is used but not copper for the recovery of metallic silver from the complex [Ag(CN)2], although electrode potentials of both zinc and copper are less than that of Ag. Explain why?

[Hint : Zinc reacts at faster rate as compared with copper, further zinc is cheaper than copper].

21. Write the composition of motlen mixture which is electrolysed to extract aluminium.

Please click the link below to download pdf file for CBSE Class 12 Chemistry notes and questions for Processes of Isolation of Elements Part C.

Tags: 

 


Click to View or Download pdf file
Click for more Chemistry Study Material

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

CBSE Reduced Syllabus Class 11 and 12

CBSE has announced major reduction in the syllabus for class 11 and class 12. There has been major changes too in the main syllabus for class 11 and 12. The prevailing health emergency in the country and at different parts of the world as well as the efforts to contain...

Class 12 Board Exams Datesheet Announced

CBSE has announced the datesheet of the remaining class 12 board exams, see below:  

TV Channels for Students by CBSE

In enhancing the students studying part, the Government is planning to introduce one standard one channel plan. The lockdown in India has adversely collapsed all the operations including schools, colleges, and workplaces with unanticipated setbacks. On behalf of the...

Board Exams Class 10 and Class 12 Datesheet 2020

CBSE has announced the datesheet for the remaining exams of class 10 and class 12 exams. The exams are going to start in July. The class 10 and 12th board exams will be conducted for the remaining 29 papers from July 1 to July 15, 2020, at various centers nominated by...

CBSE Decision on Board Exam 2020

The Class 10 and 12 exams are cancelled, and results for both 10th and 12th would be declared by July 15 based on internal exams. CBSE Class 12 students would have the option to appear for the exams at a later date. CBSE has a scheme in which marks scored in past 3...

Procedure for correction in Name and Date of Birth

Procedure for correction in Name and Date of Birth in CBSE records Name Change: Applications regarding changes in name or surname of candidates will be considered provided the changes have been admitted by the Court of law and notified in the Government Gazette before...

×
Studies Today