In terms of Ellingham diagram state why ${\mathrm{Al}}_2{\mathrm{O}}_3$ cannot be reduced by chromium.

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 36

Which reducing agent is used to reduce the oxides of less electropositive metals?

EASY

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 41

How will you purify metal like copper?

MEDIUM

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 43

Ultra pure silicon is used by electronic industry. By which method of refining pure grade silicon is obtained?

EASY

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 48

Name the most important ore of aluminium.

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 51

What is the composition of ignition mixture used in aluminothermy?

HARD

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 56

What is anodised aluminium?

EASY

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 58

List the names and formulae of two important ores of copper.

EASY

12th West Bengal Board

IMPORTANT

NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 6 - General Principles and Processes of Isolation of Elements>REVIEW EXERCISES>Q 62

Which metal is used to prevent iron sheets by the process of galvanization?