Give reasons for the following observations:
Leather gets hardened after tanning
Animal skin (hide) is colloidal in nature and has positively charged particles, whereas tanning consists of negatively charged colloidal particles. When a hide is soaked in tanning, mutual coagulation takes place and as a result, leather gets hardened.
What is the significance of leaching in the extraction of aluminium?
Is it true that under certain conditions. Mg can reduce Al2O3 and Al can reduce MgO? What are those conditions?
Titanium is a metal of modern times. It is obtained as oxide. Why it could not be extracted earlier despite its wide occurence?
Name the common elements present in the anode mud in electrolytic refining of copper. Why are they so present?
What criterion is followed for the selection of the stationary phase in chromatography?
What is the role of cryolite in the metallurgy of aluminium?
Why is zinc not extracted from zinc oxide through reduction using CO?
Mock Test Series
