When copper ii chloride reacts with sodium nitrate copper ii nitrate and sodium chloride are formed?

The balanced chemical reaction would be written as follows:

CuCl2 + 2NaNO3 = Cu(NO3)2 + 2NaCl

This is an example of a double displacement type of reaction where the ions of the reactants displaces each other forming two new substances. Hope this answers the question.

They carry out the exchange of gases as we breathe ( oxygen and carbon dioxide).