EASY
12th West Bengal Board
IMPORTANT
Earn 100

Which elements are found in their elemental state in nature?

Important Questions on General Principles and Processes of Isolation of Elements

EASY
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 76

In the purification of ores, for which of the following ores oil floatation process is helpful?

 sulphate, oxide sulphide, carbon etc.

MEDIUM
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 77
What is the role of cryolite in the extraction of pure aluminium from bauxite ore by electrolytic process?
EASY
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 78
Name a sulphide ore of copper.
MEDIUM
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 79
What are the main constituents of invar?
EASY
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 1
Predict the mode of occurrence of the highly reactive (e.g. Na)  types of  metals.
EASY
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 1
Predict the mode of occurrence of the moderately reactive (e.g. Fe)   metals.
EASY
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 1
Predict the mode of occurrence of the Noble metals reactive (e.g. Au)  types of  metals.
EASY
12th West Bengal Board
IMPORTANT
NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 2

Name the chief forms of occurrence of the following in the Earth's Crust

(i) Aluminium