Which of the following is an alloy?

What is the process of depositing a layer of gold on silver called?

$(a)$ Carbon cannot be used as a reducing agent to obtain $Mg$ from $MgO$. Why?
$(b)$ How is sodium obtained from molten sodium chloride? Give the equations of the reactions.
$(c)$ How is copper obtained from its sulphide ore? Give the equations of the reactions.

Write the chemical equations for the reactions of zinc granules with:
$(a)$ Sulphuric acid
$(b)$ Hydrochloric acid
$(c)$ Aluminium chloride
$(d)$ Sodium hydroxide
$(e)$ Nitric acid

Metallic oxides of zinc,magnesium,and copper were heated with the following metals. In which cases will you find displacement reactions taking place?

What is the typical carat value of gold used in jewelry?