When an aqueous solution of ammonia is added to an aqueous solution of cupric sulfate,which substance forms a pale blue precipitate?

What is meant by anodising? How is it done?

Write the chemical equations for the reactions of zinc granules with:
$(i)$ Sulphuric acid
$(ii)$ Hydrochloric acid
$(iii)$ Aluminium chloride
$(iv)$ Sodium hydroxide
$(v)$ Nitric acid

Which of the following methods is $NOT$ used for the concentration of an ore?

What change occurs in the concentrated ore during the roasting process?

Explain the following statements:
$(a)$ Most metal oxides are insoluble in water but some of these dissolve in water. What are these oxides and their solutions in water called?
$(b)$ At ordinary temperature,the surfaces of metals such as magnesium,aluminium,and zinc are covered with a thin layer. What is the composition of this layer? State its importance.
$(c)$ Some alkali metals can be cut with a knife.