Which furnace is used to extract iron metal from its ore?

Which type of oxide is $CO_{2}$?

$(i)$ Explain the steps for extraction of copper from its sulphide ore. Write the balanced equations involved in the process.
$(ii)$ What is meant by refining of metals? Draw a diagram of electrolytic refining of copper and name the substances used as cathode, anode, and the electrolyte.

Which metal reacts with cold water violently?

$(i)$ Define the term 'anode mud'. Name the electrode made of pure metal.
$(ii)$ Give the reactions taking place at cathode and at anode during the electrolytic refining of copper.

$(a)$ $A$ substance $X$,an oxide of a metal,is used extensively in the cement industry. This element is found in our bones also. On treatment with water,it forms a solution which turns red litmus blue. Identify $X$ and also write the chemical reaction involved.
$(b)$ Choose a metal from the following metals which reacts only with hot water: Sodium,magnesium,iron. Mention the products formed during the reaction.