Question

(i) Name the carbonate ore of zinc.
(ii) Name the compound ‘A’ formed when the above named ore is heated.
(iii) Name the process by which the zinc compound ‘A’ is formed from carbonate ore.
(iv) Name the reducing agent used during the process and write the balanced chemical equation.

Answer 1

Hint: The question mainly deals with the processes undergone by the carbonate ore of zinc in order to extract zinc metal. There are multiple steps to the process. Each process is taking place in different conditions such as heating, in a limited supply of air, or presence of a reducing agent.

Complete answer:
Let us answer the questions one by one.
(i) The carbonate ore of zinc is called Smithsonite. The compound is zinc carbonate and has the chemical formula $ZnC{O_3}.$ Smithsonite is also known as turkey fat or zinc spar.
(ii) When the carbonate ore of zinc, which is zinc carbonate $\left( {ZnC{O_3}} \right),$ is heated in a limited supply of air, it decomposes to give zinc oxide $\left( {ZnO} \right)$ and carbon dioxide as the products.
$ZnC{O_3}\xrightarrow{{Heat}}ZnO + \,C{O_2}$
Hence, the required compound ‘A’ is zinc oxide.
(iii) The process by which the zinc compound ‘A’, which is zinc oxide, is formed from carbonate ore is called Calcination. In calcination, a carbonate ore is strongly heated in the absence of air to give corresponding metal oxide as the product.
(iv) The reducing agent used to extract zinc metal from zinc oxide is carbon or coke. When zinc oxide is heated in the presence of carbon, zinc metal is produced. The balanced chemical equation for the reaction is as follows:
$ZnO + \,C \to Zn + CO$

Note:
The interaction between carbon dioxide and lime water is an important one as it is used for testing the presence of carbon dioxide gas in organic qualitative analysis and so on. The change in the appearance of the solution is very noticeable, and hence it is a good test.